Abstract
BackgroundArchaea combine bacterial-as well as eukaryotic-like features to regulate cellular processes. Halobacterium salinarum R1 encodes eight leucine-responsive regulatory protein (Lrp)-homologues. The function of two of them, Irp (OE3923F) and lrpA1 (OE2621R), were analyzed by gene deletion and overexpression, including genome scale impacts using microarrays.ResultsIt was shown that Lrp affects the transcription of multiple target genes, including those encoding enzymes involved in amino acid synthesis, central metabolism, transport processes and other regulators of transcription. In contrast, LrpA1 regulates transcription in a more specific manner. The aspB3 gene, coding for an aspartate transaminase, was repressed by LrpA1 in the presence of L-aspartate. Analytical DNA-affinity chromatography was adapted to high salt, and demonstrated binding of LrpA1 to its own promoter, as well as L-aspartate dependent binding to the aspB3 promoter.ConclusionThe gene expression profiles of two archaeal Lrp-homologues report in detail their role in H. salinarum R1. LrpA1 and Lrp show similar functions to those already described in bacteria, but in addition they play a key role in regulatory networks, such as controlling the transcription of other regulators. In a more detailed analysis ligand dependent binding of LrpA1 was demonstrated to its target gene aspB3.
Highlights
IntroductionArchaea combine bacterial-as well as eukaryotic-like features to regulate cellular processes
Archaea combine bacterial-as well as eukaryotic-like features to regulate cellular processes.Halobacterium salinarum R1 encodes eight leucine-responsive regulatory protein (Lrp)-homologues
LrpA1 and Lrp show similar functions to those already described in bacteria, but in addition they play a key role in regulatory networks, such as controlling the transcription of other regulators
Summary
Archaea combine bacterial-as well as eukaryotic-like features to regulate cellular processes. Halobacterium salinarum R1 encodes eight leucine-responsive regulatory protein (Lrp)-homologues. The basal transcription apparatus in Archaea shows similarity to the eukaryotic RNA polymerase (RNAP) II system [1,2,3,4]. Archaeal promoter sequences and the core proteins RNA polymerase (RNAP), TATA-binding protein (TBP), and the transcription factor IIB homologue (TFB) are structurally and functionally related to their eukaryotic counterparts [2,5]. The basal transcriptional complex is composed of eukaryotic-like components, archaeal regulatory proteins are often homologous to bacterial regulators [6]. One group of bacterial regulators which have been found in all archaeal genomes belongs to the Lrp/AsnC family (leucineresponsive regulatory protein (Lrp), asparagine synthase. As a global regulator of transcription, Lrp is believed to coordinate cellular
Sign-in/Register to view highlights & summary 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.
