Abstract
The Pseudomonas oleovorans alkBAC operon encodes seven proteins, of which at least three are involved in alkane hydroxylase (alkBA) and alkanol dehydrogenase (alkC) activities. We have determined the nucleotide sequence of the 2.5-kilobase pair alkA region and analyzed the role of its translation products in alkane oxidation. The alkA region contains three coding sequences, encoding two related rubredoxins (alkF and alkG) of 14- and 18-kDa molecular mass and a 52-kDa aldehyde dehydrogenase (alkH). Deletion analysis indicated that neither the 14-kDa alkF gene product (rubredoxin 1) nor the amino-terminal part of the 18-kDa alkG gene product (rubredoxin 2) is required for alkane hydroxylase activity in vivo. The product of the alkH cistron restores growth of a P. oleovorans aldehyde dehydrogenase mutant on aliphatic alcohols and aldehydes. Its amino acid sequence shows considerable homology to previously characterized aldehyde dehydrogenases from mammalian and fungal origin. The nucleotide composition of the alk genes (47% G + C) differs considerably from the G + C content of the P. oleovorans genome suggesting that the alk regulon may originate from an unrelated organism.
Highlights
The Pseudomonas oleovorans alkBAC operon encodes seven proteins, of which at least three are involved in alkane hydroxylaseand alkanol dehydrogenaseactivities
An unexpected result was the complementation of the alk1145 mutation by pGEc284.pGEc284 carries a fusion between the two rubredoxin cistrons which results in a hybrid duced the nomenclature shown for the seven cistrons encoded by the gene encoding a 184 amino acid translation product
We have shown that thealkA region of the alkBAC operon encodes three proteins of which one (AlkG) is essential for alkane hydroxylation and one (AlkH) weakly complements a P. oleouorans aldehyde dehydrogenase mutation
Summary
P. oleovorans aldehyde dehydrogenase mutant on aliphatic alcohols and aldehydes. Its amino acid sequence shows considerable homology to previously characterized aldehyde dehydrogenases from mammalian and fungal origin. AlkBAC operon encodes six or seven peptides (Eggink et al, 1987a) The first of these is the 45.7-kDa membrane-bound component of alkane hydroxylase, the product of the alkB gene, whichwe have described in detail in the preceding paper (Kok et al, 1989). Two of the translation products of the alkA region have previously been identified (Eggink et al, 1987a).Nucleotide sequencing indicated the presence of three large open reading frames which we have designated as follows: alkF (which encodes a 14-kDa peptide), alkG (which contains coding capacity for an 18-kDapeptide), andalkH (which encodes a 52-kDa polypeptide previously tentatively identified as rubredoxin reductase). In this paper we present the nucleotide sequence of the alkF, alkG, and alkH cistrons located in alM Comparison of these sequences to known sequences show that alkH encodes an aldehyde dehydrogenase rather thanrubredoxin reductase, while alkF and alkG encode two closely related rubredoxins.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
