Physical Sciences and Mathematics Commons^™

Plp And Gaba Trigger Gabr-Mediated Transcription Regulation In Bacillus Subtilis Via External Aldimine Formation, Rui Wu, Ruslan Sanishvili, Boris R. Belitsky, Jose I. Juncosa, Hoang V. Le, Helaina J. S. Lehrer, Michael Farley, Richard B. Silverman, Gregory A. Petsko, Dagmar Ringe, Dali Liu

Chemistry: Faculty Publications and Other Works

The Bacillus subtilis protein regulator of the gabTD 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, ( …