GDP Formation Research Articles

GDP Structure and Economic Performance in Sub-Saharan Countries

Africa belongs to important regions of the world economy with specific problems distinguishing this part of the world from other regions. The region is suffering because of limited economy structure and high level of poverty. Low economic performance ranks most of African countries among the worldwide poorest ones (both from the point of view of total economy performance and also individuals living standards); the development is hindered by political instability and also by other accompanied problems as high level of corruption, deficit of democracy, low level of education, limited investments, criminality, local conflicts, civil wars etc. On the other hand, African natural, economy and social resources and unexploited opportunities in many areas offer a potential for a considerable economic development. Understanding the current economic position of African states thus may reveal causes of problematic development and outline ways to overcome existing shortcomings. The aim of the paper is to analyze main changes in area of GDP structure formation (agricultural, industrial and services sector share in GDP and value performance) which have occurred in selected African (Sub-Saharan) countries. Changes are analyzed both in relation to the total GDP and GDP per capita. The authors identify main trends of economic development in the Sub-Saharan region and to specify differences among Sub-Saharan countries with the intention to identify particular groups of African countries according to their economic structure and to identify differences in their GDP formation.

Capital Formation in Thailand: Its Importance and Determinants

Using the dataset that comprises annual data during 1979 and 2012 and obtained from various sources, this study examines the importance of capital formation to Thai economy and what driving forces influence capital formation. The results show that real GDP and capital formation are cointegrated, and capital formation imposes a positive impact on real GDP in the long run. It is also found that stock market liquidity measured by stock market capitalization rather than foreign direct investment plays important role in capital accumulation process. These findings give some policy implications.

TASK FOR POST-CRISIS IN ROMANIA: THE DEVELOPMENT OF INDUSTRY

The present paper illustrates the role of industry in economic and social development of Romania, in the context of the propagated effects of the contemporary economic and financial crisis and mission that is in the recovery of gaps in relation to EU countries. The dynamic of the industrial sector after 1989, highlighting the continuing decline in its contribution to the GDP formation and changing industry structure in favor of industries producing consumer goods. The situation has changed, however, after the crisis, the industry producing capital goods coming back in force, and hosting the entire sector. Significant is that the development of the Romanian industry must integrate into a viable and sustainable formula, scientific research and technological development with environmental quality. Moreover, the qualitative and quantitative dimensions of industrial development in Romania should be integrated in the dynamic dimensions of the EU, with all the implications and costs derived from this, in the short term. The plea for industrial development in the post-crisis period is supported by the need to ensure a solid foundation for the development of other economic activities specific to the primary and tertiary sectors.

EVALUASI KEBIJAKAN PENGELOLAAN KAWASAN PANTAI UTARA KABUPATEN BEKASI DALAM PENINGKATAN KESEJAHTERAAN MASYARAKAT PESISIR

The objectives of this research are to (i) Evaluate the desired results in the policies concerning spatial planning in North Coast Special Area Bekasi; (ii) analyze the people's views in the framework of the implementation of policies concerning the plan space utilization patterns in the North Coast Special Area Bekasi; and (iii) analyze the positive impact on gross domestic product of policy implementation plan regarding the utilization of space, in the North Coast Special Area Bekasi. This research was conducted in Coastal Areas Bekasi which consists of three districts namely Babelan District, District Tarumajaya, and Muara Gembong District covering an area of 24615.06 ha. Analysis of the data has been obtained from field data collection activities. Examination of the data in this research done by triangulation technique which is based on sources and methods to confirm the interview data, observation, questionnaires and documents. This study concludes, as follow: 1) The authorities in order to prioritize the utilization and management of coastal development Bekasi in the industrial sector; 2) The private sector to give priority to the industrial sector increased employment, achieve optimization ofthe utilization of coastal areas; 3) Community considers that the main priority is the priohty use of the industry, except for the prevention of environmental degradation, conservation, cultural activities and cultural goals to prioritize transportation and tourism, 4) The view NGOs to prioritize the utilization ofthe industryas a major priority in orderto develop the coastal villages Bekasi, and 5) Banking holds to the phority use ofmost ofthe industrial sector. Third, the positive impact the implementation of policies conceming the utilization of space in North Coast Special Area Bekasi to increase gross domestic income can be viewed through the largest contribution to GDP formation Bekasi.

Insight into temperature dependence of GTPase activity in human guanylate binding protein-1.

Interferon-γ induced human guanylate binding protein-1(hGBP1) belongs to a family of dynamin related large GTPases. Unlike all other GTPases, hGBP1 hydrolyzes GTP to a mixture of GDP and GMP with GMP being the major product at 37°C but GDP became significant when the hydrolysis reaction was carried out at 15°C. The hydrolysis reaction in hGBP1 is believed to involve with a number of catalytic steps. To investigate the effect of temperature in the product formation and on the different catalytic complexes of hGBP1, we carried out temperature dependent GTPase assays, mutational analysis, chemical and thermal denaturation studies. The Arrhenius plot for both GDP and GMP interestingly showed nonlinear behaviour, suggesting that the product formation from the GTP-bound enzyme complex is associated with at least more than one step. The negative activation energy for GDP formation and GTPase assay with external GDP together indicate that GDP formation occurs through the reversible dissociation of GDP-bound enzyme dimer to monomer, which further reversibly dissociates to give the product. Denaturation studies of different catalytic complexes show that unlike other complexes the free energy of GDP-bound hGBP1 decreases significantly at lower temperature. GDP formation is found to be dependent on the free energy of the GDP-bound enzyme complex. The decrease in the free energy of this complex at low temperature compared to at high is the reason for higher GDP formation at low temperature. Thermal denaturation studies also suggest that the difference in the free energy of the GTP-bound enzyme dimer compared to its monomer plays a crucial role in the product formation; higher stability favours GMP but lower favours GDP. Thus, this study provides the first thermodynamic insight into the effect of temperature in the product formation of hGBP1.

An Activating Helix Switch at the Rhodopsin-Transducin Interface

Extracellular signals prompt G protein-coupled receptors (GPCRs) to adopt an active conformation (R∗) and to catalyze GDP/GTP exchange in the α-subunit of intracellular G proteins (Gαβγ). Kinetic analysis of transducin (Gtαβγ) activation has shown that an intermediary R∗·Gtαβγ·GDP complex is formed which precedes GDP release and formation of the nucleotide-free R∗·G protein complex. Based on this reaction sequence we explore the dynamic interface between the proteins during formation of these complexes. We start from the R∗ conformation stabilized by a Gtα C-terminal peptide (GαCT) obtained from crystal structures of the GPCR opsin. Molecular modeling allows reconstruction of the fully elongated C-terminal α-helix of Gtα (α5) and shows how α5 can be docked to the open binding site of R∗. Two modes of interaction are found. One of them - termed stable or S-interaction - matches the position of the GαCT peptide in the crystal structure and reproduces the hydrogen bridge networks between the C-terminal reverse turn of GαCT and conserved E(D)RY and NPxxY(x)5,6F regions of the GPCR. The alternative fit - termed intermediary or I-interaction - is distinguished by a tilt and significant clockwise rotation of α5 relative to the S-interaction. It shows different α5 contacts with the NPxxY(x)5,6F region and the second cytoplasmic loop of R∗. From the two α5 interactions, we derive a ‘helix switch’ mechanism for the transition of R∗·Gtαβγ·GDP to the nucleotide-free R∗·G protein complex. It illustrates how α5 acts as a transmission rod to propagate the conformational change from the receptor-G protein interface to the nucleotide binding site. The results are discussed in light of the recent structure of the β2 adrenergic receptor-Gs protein complex. A detailed mechanism of complex formation and GDP release is derived.

Impact of FDI on GDP: A Comparative Study of China and India

Present paper attempts to investigate the effect of FDI on economic growth of China and India. To take care ofthe issue of structural change in economy, time period of the study is taken to be 1993-2009. First of all we builtour modified growth model from basic growth model. The factors included in growth model were GDP, HumalCapital, Labor Force, FDI and Gross Capital Formation, among which GDP was dependent variable while restfour were independent variables. After running OLS (Ordinary Least Square) method of regression we foundthat 1% increase in FDI would result in 0.07% increase in GDP of China and 0.02% increase in GDP of India.We also found that China’s growth is more affected by FDI, than India’s growth. The study also providespossible reasons behind China’s great show of FDI and the lessons India should learn from China for betterutilization of FDI.

Electricity consumption and economic growth in Burkina Faso: A cointegration analysis

This study empirically establishes the direction of causality between electricity consumption and economic growth in Burkina Faso for the period 1968–2003. The bounds test yields evidence of cointegration between electricity consumption, GDP, and capital formation when electricity consumption and GDP are used as dependent variable. Causality results indicate that there is no significant causal relationship between electricity consumption and investment. Estimates, however, detect in the long-run a bidirectional causal relationship between electricity use and real GDP. There is also evidence of a positive feedback causal relationship between GDP and capital formation. Burkina Faso is therefore an energy dependent country. It is also a country in which electricity consumption is growing with the level of income. All of this shows that electricity is a significant factor in socio-economic development in Burkina Faso; as such, energy policy must be implemented to ensure that electricity generates fewer potential negative impacts.

Structural and kinetic modeling of an activating helix switch in the rhodopsin-transducin interface

Extracellular signals prompt G protein-coupled receptors (GPCRs) to adopt an active conformation (R*) and catalyze GDP/GTP exchange in the alpha-subunit of intracellular G proteins (Galphabetagamma). Kinetic analysis of transducin (G(t)alphabetagamma) activation shows that an intermediary R*xG(t)alphabetagamma.GDP complex is formed that precedes GDP release and formation of the nucleotide-free R*xG protein complex. Based on this reaction sequence, we explore the dynamic interface between the proteins during formation of these complexes. We start from the R* conformation stabilized by a G(t)alpha C-terminal peptide (GalphaCT) obtained from crystal structures of the GPCR opsin. Molecular modeling allows reconstruction of the fully elongated C-terminal alpha-helix of G(t)alpha (alpha5) and shows how alpha5 can be docked to the open binding site of R*. Two modes of interaction are found. One of them--termed stable or S-interaction--matches the position of the GalphaCT peptide in the crystal structure and reproduces the hydrogen-bonding networks between the C-terminal reverse turn of GalphaCT and conserved E(D)RY and NPxxY(x)(5,6)F regions of the GPCR. The alternative fit--termed intermediary or I-interaction--is distinguished by a tilt (42 degrees ) and rotation (90 degrees ) of alpha5 relative to the S-interaction and shows different alpha5 contacts with the NPxxY(x)(5,6)F region and the second cytoplasmic loop of R*. From the 2 alpha5 interactions, we derive a "helix switch" mechanism for the transition of R*xG(t)alphabetagamma.GDP to the nucleotide-free R*xG protein complex that illustrates how alpha5 might act as a transmission rod to propagate the conformational change from the receptor-G protein interface to the nucleotide binding site.

Export‐oriented small and medium industry clusters in Indonesia

PurposeThe Indonesian government has been trying to support the development of small and medium enterprises (SMEs) in the country, as these enterprises are expected to play a crucial role not only for employment creation but also for GDP formation and export development. The paper aims to address the following three questions. First, are networks important for the development of SME clusters, especially for those involved in export activities? Second, in what type of clusters are networks well developed? Third, what is the role of government; does it also play as an important network for SME cluster development?Design/methodology/approachThis paper is based on an ongoing research on the importance of networks in the development of export‐oriented SME clusters in Indonesia. Although the paper also discusses other important issues related to the development of SMEs in the country, i.e. constraints facing the enterprises and women entrepreneurs, the paper focuses on the importance of networks.FindingsFirst, SMEs are of overwhelming importance to Indonesia because they account for more than 90 percent of all firms outside of the agricultural sector. Second, the main constraints faced by small entrepreneurs are, lack of finance and difficulties in marketing. Third, the representation of women entrepreneurs in Indonesia is still relatively low which can be attributed to various factors, e.g. low level of education and lack of training opportunities that make Indonesian women severely disadvantaged in both the economy and society. Finally, although in general Indonesia is not well represented with small and medium industrial clusters that feed into global commodity chains, some clusters have gradually become export‐oriented. Among many factors, well developed networks especially with traders, trading houses, and foreign tourists are indeed an important factor for their increasingly export activities. Even these agents have played more important role than supports from government for their successful export.Originality/valueThe paper examines the importance of networks for the export‐oriented SME clusters in Indonesia.

Polyphosphatase Activity of CthTTM, a Bacterial Triphosphate Tunnel Metalloenzyme

Triphosphate tunnel metalloenzymes (TTMs) are a superfamily of phosphotransferases with a distinctive active site located within an eight-stranded beta barrel. The best understood family members are the eukaryal RNA triphosphatases, which catalyze the initial step in mRNA capping. The RNA triphosphatases characteristically hydrolyze nucleoside 5'-triphosphates in the presence of manganese and are inept at cleaving inorganic tripolyphosphate. We recently identified a TTM protein from the bacterium Clostridium thermocellum (CthTTM) with the opposite substrate preference. Here we report that CthTTM catalyzes hydrolysis of guanosine 5'-tetraphosphate to yield GTP and P(i) (K(m) = 70 microm, k(cat) = 170 s(-1)) much more effectively than it converts GTP to GDP and P(i) (K(m) = 70 microm, k(cat) = 0.3 s(-1)), implying that a nucleoside interferes when positioned too close to the tunnel entrance. CthTTM is capable of quantitatively cleaving diadenosine hexaphosphate but has feeble activity with shorter derivatives diadenosine tetraphosphate and diadenosine pentaphosphate. We propose that the tunnel opens to accommodate the dumbbell-shaped diadenosine hexaphosphate and then closes around it to perform catalysis. We find that CthTTM can exhaustively hydrolyze a long-chain inorganic polyphosphate, a molecule that plays important roles in bacterial physiology. CthTTM differs from other known polyphosphatases in that it yields a approximately 2:1 mixture of P(i) and PP(i) end products. Bacterial/archaeal TTMs have a C-terminal helix located near the tunnel entrance. Deletion of this helix from CthTTM exerts pleiotropic effects. (i) It suppresses hydrolysis of guanosine 5'-tetraphosphate and inorganic PPP(i); (ii) it stimulates NTP hydrolysis; and (iii) it biases the outcome of the long-chain polyphosphatase reaction more strongly in favor of P(i) production. We discuss models for substrate binding in the triphosphate tunnel.

Is Economic Growth Sustainable in Romania?

The last events which took place after the 1st January 2007 and Romania's admission in the European Union imply a sustainable and continuous economic growth, in order to reduce economic and social disparities between our country, EU average and other EU members, through a mobilization of the intern capital and labour force potential. Given this context, the paper aims at identifying and explaining, through a retrospective analysis, GDP fluctuations and tries to evaluate, using the aggregate supply-demand model, the contribution of each structural element in GDP formation and increase. Finally, the article proposes directions of action for continuing the sustainable development of Romania and reducing the gaps between this country and other EU members.

Development of SME and Women Entrepreneurs in a Developing Country: The Indonesian Story

In Indonesia the government has been trying to support the development of small and medium enterprises (SMEs) as these enterprises are expected to play a crucial role, not only in employment creation, GDP formation, and export development, but also especially as a means to developed women entrepreneurs, particularly in rural areas. This paper examines the current developments of SMEs, constraints on their current development, the involvement of women as entrepreneurs in SMEs, and the effectiveness of government SME development programs in Indonesia. The paper identifies some important facts. First, SMEs are of overwhelming importance in Indonesia, as they account for more than 90% of all firms outside the agricultural sector. Second, the main constraints faced by small entrepreneurs are cumbersome and onerous business regulations and restrictions, lack of finance, and limits in human resource and technological capabilities. Third, the representation of women entrepreneurs is still relatively low which can be attributed to factors such as low level of education and cultural or religious constraints. Finally, the government has been the most important supporting agency for SMEs. However, evidence on the effectiveness of government programs to support SME development is mixed.

Energetics of Interaction between the G-protein Chaperone, MeaB, and B12-dependent Methylmalonyl-CoA Mutase

MeaB is an auxiliary protein that supports the function of the radical B(12)-dependent enzyme, methylmalonyl-CoA mutase, although its precise role is not understood. Mutations in the human homolog of MeaB, MMAA, lead to methylmalonic aciduria, an inborn error of metabolism that can be fatal. To obtain insights into the function of this recently discovered protein, we have characterized the entropic and enthalpic contributions to DeltaGdegree (assoc) for complexation of MeaB (in the presence and absence of nucleotides) with methylmalonyl-CoA mutase (in the presence and absence of cofactor). The dissociation constant for binding of methylmalonyl-CoA mutase and MeaB ranges from 34 +/- 4 to 524 +/- 66 nm, depending on the combination of nucleotide and mutase form. Holomutase binds MeaB 15-fold more tightly when the nonhydrolyzable GTP analog, GMPPNP, is bound versus GDP. In contrast, the apomutase binds MeaB with similar affinity in the presence of either nucleotide. Our studies reveal that a large structural rearrangement accompanies interaction between these proteins and buries between approximately 4000 and 8600A(2) of surface area, depending on the combination of ligands in the active sites of the two proteins. Furthermore, we demonstrate that MeaB binds GTP and GDP with similar affinity (K(d) of 7.3 +/- 1.9 and 6.2 +/- 0.7 microm, respectively at 20 degrees C) and has low intrinsic GTPase activity (approximately 0.04 min(-1) at 37 degrees C), which is stimulated approximately 100-fold by methylmalonyl-CoA mutase. These studies provide insights into the energetics of interaction between the radical enzyme methylmalonyl-CoA mutase and MeaB, which are discussed.

AGRICULTURAL PENSIONS – MAJOR ISSUES AND POSSIBILITIES OF IMPROVEMENT

The present paper points out all the problems regarding the increase of manpower employment rate, the demand provided by Lisbon Agenda. Among other actions which have to be undertaken, the growth of the occupancy rate in Romania inevitably implies a solution for the serious trouble generated by the Romanian agriculture, contributing to the formation of the GDP which is three times less important than the total share of employed manpower. The difference is provided not only by the insufficient technical endowment of Romanian agricuture, but also by the large number of people working in agriculture (40% according to official statistics). On the other side, the increase of the employment rate in Romania will generate a new issue for governers that of: finding necessary resources for the retirement payment, including public and agricultural retirements. Considering the high proportion between the number of pensioners and that of working people, respectively 4.5 million pensioners reported to 6 million employees, the need for the improvement of the pension system in Romania becomes obviuos.

Tax Policy in India

The tax reforms of recent years in India are based on Chelliah’s recommendations of simple broad-based taxes with a moderate and limited number of rates. The reduction in direct tax rates in the economy has not only increased revenue collection but also accelerated economic growth. This article aims to investigate the effect of India’s tax policy on private capital formation. A time series analysis of data for the economy for the period 1950–51 to 1994–95 reveals that a one percent increase in the direct tax ratio has led to a reduction of 0.12 percent in the ratio of private capital formation to GDP. The article also examines whether there is any gain in opting for an expenditure tax to promote savings and capital formation in the economy. The major problem facing the Indian direct tax system is evasion of income taxes. The article concludes that an expenditure tax is a powerful tool to combat evasion

National Health Accounts development: lessons from Thailand.

National Health Accounts (NHA) are an important tool to demonstrate how a country's health resources are spent, on what services, and who pays for them. NHA are used by policy-makers for monitoring health expenditure patterns; policy instruments to re-orientate the pattern can then be further introduced. The National Economic and Social Development Board (NESDB) of Thailand produces aggregate health expenditure data but its estimation methods have several limitations. This has led to the research and development of an NHA prototype in 1994, through an agreed definition of health expenditure and methodology, in consultation with peer and other stakeholders. This is an initiative by local researchers without external support, with an emphasis on putting the system into place. It involves two steps: firstly, the flow of funds from ultimate sources of finance to financing agencies; and secondly, the use of funds by financing agencies. Five ultimate sources and 12 financing agencies (seven public and five private) were identified. Use of consumption expenditures was listed under four main categories and 32 sub-categories. Using 1994 figures, we estimated a total health expenditure of 128,305.11 million Baht; 84.07% consumption and 15.93% capital formation. Of total consumption expenditure, 36.14% was spent on purchasing care from public providers, with 32.35% on private providers, 5.93% on administration and 9.65% on all other public health programmes. Public sources of finance were responsible for 48.79% and private 51.21% of the total 1994 health expenditure. Total health expenditure accounted for 3.56% of GDP (consumption expenditure at 3.00% of GDP and capital formation at 0.57% of GDP). The NESDB consumption expenditure estimate in 1994 was 180,516 million Baht or 5.01% of GDP, of which private sources were dominant (82.17%) and public sources played a minor role (17.83%). The discrepancy of consumption expenditure between the two estimates is 2.01% of GDP. There is also a large difference in the public and private proportion of consumption expenses, at 46:54 in NHA and 18:82 in NESDB. Future NHA sustainable development is proposed. Firstly, we need more accurate aggregate and disaggregated data, especially from households, who take the lion's share of total expenditure, based on amended questionnaires in the National Statistical Office Household Socio-Economic Survey. Secondly, partnership building with NESDB and other financing agencies is needed in the further development of the financial information system to suit the biennial NHA report. Thirdly, expenditures need breaking down into ambulatory and inpatient care for monitoring and the proper introduction of policy instruments. We also suggest that in a pluralistic health care system, the breakdown of spending on public and private providers is important. Finally, a sustainable NHA development and utilization of NHA for planning and policy development is the prime objective. International comparisons through collaborative efforts in standardizing definition and methodology will be a useful by-product when developing countries are able to sustain their NHA reports.

ATP/GTP hydrolysis is required for oxazole and thiazole biosynthesis in the peptide antibiotic microcin B17.

In the maturation of the Escherichia coli antibiotic Microcin B17, the product of the mcbA gene is modified posttranslationally by the multimeric Microcin synthetase complex (composed of McbB, C, and D) to cyclize four Cys and four Ser residues to four thiazoles and four oxazoles, respectively. The purified synthetase shows an absolute requirement for ATP or GTP in peptide substrate heterocyclization, with GTP one-third as effective as ATP in initial rate studies. The ATPase/GTPase activity of the synthetase complex is conditional in that ADP or GDP formation requires the presence of substrate; noncyclizable versions of McbA bind to synthetase, but do not induce the NTPase activity. The stoichiometry of ATP hydrolysis and heterocycle formation is 5:1 for a substrate that contains two potential sites of modification. However, at high substrate concentrations (>50Km) heterocycle formation is inhibited, while ATPase activity occurs undiminished, consistent with uncoupling of NTP hydrolysis and heterocycle formation at high substrate concentrations. Sequence homology reveals that the McbD subunit has motifs reminiscent of the Walker B box in ATP utilizing enzymes and of motifs found in small G protein GTPases. Mutagenesis of three aspartates to alanine in these motifs (D132, D147, and D199) reduced Microcin B17 production in vivo and heterocycle formation in vitro, suggesting that the 45 kDa McbD has a regulated ATPase/GTPase domain in its N-terminal region necessary for peptide heterocyclization.

Kinetic and Thermodynamic Characterizations of Yeast Guanylate Kinase

Yeast guanylate kinase was expressed at high level in Escherichia coli using pET-17b vector. It was purified to homogeneity by a simple two-column procedure with an average yield of approximately 100 mg/liter. The steady-state kinetic parameters for both forward and reverse reactions were determined by initial velocity measurements. The turnover numbers (kcat) were 394 s-1 for the forward reaction (formation of ADP and GDP) and 90 s-1 for the reverse reaction (formation of ATP and GMP). Km values were 0.20, 0. 091, 0.017, and 0.097 mM for MgATP, GMP, MgADP, and GDP, respectively. Analysis of the initial velocity patterns indicated a sequential mechanism. GMP was found to have partial substrate inhibition. The substrate inhibition was not competitive with MgATP and could be attributed to formation of the abortive complex guanylate kinase.MgADP.GMP. The equilibrium constant of the reaction was measured under various conditions by NMR and a radiometric assay. The results showed that the steady-state kinetic parameters were consistent with the thermodynamic constant. NMR titration and equilibrium dialysis showed that both substrates and products could bind to free guanylate kinase. The dissociation constants were 0.090, 0.18, 0.029, 0.084, and 0.12 mM for MgATP, ATP, GMP, MgADP, and GDP, respectively. Viscosity-dependent kinetics was used to identify the rate-limiting steps of the reaction. The results indicated that the reaction rate is largely controlled by the chemical step.

Regulation of glucagon receptor binding. Lack of effect of Mg and preferential role for GDP.

The effects of Mg2+ and guanine nucleotides on glucagon binding to its receptor were studied using [125I-Tyr10]monoiodoglucagon. Contrary to findings with beta-adrenergic receptors, high affinity binding of the stimulatory hormone was not dependent on Mg2+ and low affinity binding could be obtained on nucleotide addition regardless of presence of Mg2+. GDP, guanyl-5'-yl thiophosphate (GDP beta S), GTP, and guanyl-5'-yl imidodiphosphate (GMP-P(NH)P) were all able to induce low affinity hormone binding. Since the Ns component of adenylyl cyclase, with which the receptor interacts, is inactive in stimulating the catalytic component C of adenylyl cyclase in the absence of Mg2+, both before and after GDP addition, it is suggested that Ns has at least two domains that change conformation independently of each other: a r domain, that interacts with the receptor and confers to it high affinity binding, and a c domain, that interacts with the catalyst C and stimulates it. It is suggested further that Ns is r+c- when stabilizing the receptor in its conformation with high affinity for hormone, and r-c- when under the influence of GDP which results in the receptor adopting the conformation that exhibits low affinity for the hormone. Comparison of potencies of the four nucleotides to induce low affinity binding showed that GDP and GDP beta S were equipotent and 10 times more potent than GTP and 100 times more potent than GMP-P(NH)P. Under the conditions used it was impossible to substantiate that the effects of GTP or GMP-P(NH)P were not due to formation of GDP from GTP or presence of GDP-like material in GMP-P(NH)P. It is suggested that, contrary to widely held opinions, GDP and GDP-like compounds, and not GTP or its analogs, are responsible for the lowering of the affinity of adenylyl cyclase stimulating receptors for their hormones or agonists. Furthermore, the experiments suggest that the c+ conformation of the c domain of Ns co-exists with the r+ and not the r- conformation of its r domain.