Structural highlights
Function
[GABR_BACSU] Activates the transcription of the gabTD operon. Is also a repressor of its own expression, both in the presence and absence of GABA. Binds specifically to the DNA region overlapping the -35 region of the gabT promoter and the -10 and +1 regions of the gabR promoter. Principally regulates the utilization of gamma-aminobutyrate.[1] [2]
Publication Abstract from PubMed
Bacillus subtilis GabR (BsGabR) is involved in the gamma-aminobutyric acid (GABA) catabolism as a transcriptional regulator, consisting of an N-terminal helix-turn-helix DNA-binding domain and a C-terminal aminotransferase-like (AT-like) domain. Research on the C-terminal AT-like domain of BsGabR (BsGabR-CTD) has focused on the interaction with GABA as an effector, but most its functional details remain unclear. To understand the underlying mechanism, we report the crystal structure of BsGabR-CTD in complex with pyridoxal 5'-phosphate (PLP) and GABA at 2.0 A resolution. The structure of ligand-bound BsGabR-CTD revealed two distinct monomeric states in a homodimer. One subunit is a closed-form containing the PLP-GABA adduct, and the other subunit is a PLP-bound open-form. Our structural studies provide a detailed mechanism indicating that the open-to-closed transition by the binding of GABA induces the conformational rearrangement of BsGabR-CTD, which may trigger the activation of transcription.
Crystal structure of the C-terminal domain of Bacillus subtilis GabR reveals a closed conformation by gamma-aminobutyric acid binding, inducing transcriptional activation.,Park SA, Park YS, Lee KS Biochem Biophys Res Commun. 2017 May 27;487(2):287-291. doi:, 10.1016/j.bbrc.2017.04.052. Epub 2017 Apr 12. PMID:28412355[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Belitsky BR, Sonenshein AL. GabR, a member of a novel protein family, regulates the utilization of gamma-aminobutyrate in Bacillus subtilis. Mol Microbiol. 2002 Jul;45(2):569-83. PMID:12123465
- ↑ Belitsky BR. Bacillus subtilis GabR, a protein with DNA-binding and aminotransferase domains, is a PLP-dependent transcriptional regulator. J Mol Biol. 2004 Jul 16;340(4):655-64. PMID:15223311 doi:http://dx.doi.org/10.1016/j.jmb.2004.05.020
- ↑ Park SA, Park YS, Lee KS. Crystal structure of the C-terminal domain of Bacillus subtilis GabR reveals a closed conformation by gamma-aminobutyric acid binding, inducing transcriptional activation. Biochem Biophys Res Commun. 2017 May 27;487(2):287-291. doi:, 10.1016/j.bbrc.2017.04.052. Epub 2017 Apr 12. PMID:28412355 doi:http://dx.doi.org/10.1016/j.bbrc.2017.04.052
