Structure of the Proteus vulgaris HigB-(HigA)2-HigB toxin-antitoxin complex.

ABSTRACT: Bacterial toxin-antitoxin (TA) systems regulate key cellular processes to promote cell survival during periods of stress. During steady-state cell growth, antitoxins typically interact with their cognate toxins to inhibit activity presumably by preventing substrate recognition. We solved two x-ray crystal structures of the Proteus vulgaris tetrameric HigB-(HigA)2-HigB TA complex and found that, unlike most other TA systems, the antitoxin HigA makes minimal interactions with toxin HigB. HigB adopts a RelE family tertiary fold containing a highly conserved concave surface where we predict its active site is located. HigA does not cover the solvent-exposed HigB active site, suggesting that, in general, toxin inhibition is not solely mediated by active site hindrance by its antitoxin. Each Hig

SUBMITTER: Schureck MA 

PROVIDER: S-EPMC3887174 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature