Crystal structure of the VapBC toxin-antitoxin complex from Shigella flexneri reveals a hetero-octameric DNA-binding assembly.

ABSTRACT: Toxin-antitoxin (TA) loci are common in archaea and prokaryotes and allow cells to rapidly adapt to changing environmental conditions through release of active regulators of metabolism. Many toxins are endonucleases that target cellular mRNA and tRNAs, while the antitoxins tightly wrap around the toxins to inhibit them under normal circumstances. The antitoxins also bind to operators in the promoter regions of the cognate TA operon and thereby regulate transcription. For enteric vapBC TA loci, the VapC toxins specifically cleave tRNA(fMet) and thus down-regulate protein synthesis. Here, we describe the crystal structure of the intact Shigella flexneri VapBC TA complex, determined to 2.7 Å resolution. Both in solution and in the crystal structure, four molecules of each protein combine to f

SUBMITTER: Dienemann C 

PROVIDER: S-EPMC3384007 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature