5T4L

PLP and GABA Trigger GabR-Mediated Transcription Regulation in Bacillus subsidies via External Aldimine Formation

5T4L の概要

• エントリーDOI: 10.2210/pdb5t4l/pdb
• 関連するPDBエントリー: 5T4K
• 分子名称: Aspartate aminotransferase, (4R)-4-amino-6-{3-hydroxy-2-methyl-5-[(phosphonooxy)methyl]pyridin-4-yl}hexanoic acid (3 entities in total)
• 機能のキーワード: gabr, mocr, plp, gaba, external aldimine, transferase
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 43967.50

構造登録者

Wu, R.,Sanishvili, R.,Belitsky, B.R.,Juncosa, J.I.,Le, H.V.,Lehrer, H.J.S.,Farley, M.,Silverman, R.B.,Petsko, G.A.,Ringe, D.,Liu, D. (登録日: 2016-08-29, 公開日: 2017-03-29, 最終更新日: 2024-11-20)

主引用文献

Wu, R.,Sanishvili, R.,Belitsky, B.R.,Juncosa, J.I.,Le, H.V.,Lehrer, H.J.,Farley, M.,Silverman, R.B.,Petsko, G.A.,Ringe, D.,Liu, D.
PLP and GABA trigger GabR-mediated transcription regulation in Bacillus subtilis via external aldimine formation.
Proc. Natl. Acad. Sci. U.S.A., 114:3891-3896, 2017

PubMed Abstract: The protein regulator of the operon and its own gene (GabR) is a transcriptional activator that regulates transcription of γ-aminobutyric acid aminotransferase (GABA-AT; GabT) upon interactions with pyridoxal-5'-phosphate (PLP) and GABA, and thereby promotes the biosynthesis of glutamate from GABA. We show here that the external aldimine formed between PLP and GABA is apparently responsible for triggering the GabR-mediated transcription activation. Details of the "active site" in the structure of the GabR effector-binding/oligomerization (Eb/O) domain suggest that binding a monocarboxylic γ-amino acid such as GABA should be preferred over dicarboxylic acid ligands. A reactive GABA analog, ()-4-amino-5-fluoropentanoic acid (AFPA), was used as a molecular probe to examine the reactivity of PLP in both GabR and a homologous aspartate aminotransferase (Asp-AT) from as a control. A comparison between the structures of the Eb/O-PLP-AFPA complex and Asp-AT-PLP-AFPA complex revealed that GabR is incapable of facilitating further steps of the transamination reaction after the formation of the external aldimine. Results of in vitro and in vivo assays using full-length GabR support the conclusion that AFPA is an agonistic ligand capable of triggering GabR-mediated transcription activation via formation of an external aldimine with PLP.

PubMed: 28348215
DOI: 10.1073/pnas.1703019114

実験手法

X-RAY DIFFRACTION (1.53 Å)