Antitoxin control of optimal transcriptional repression in the atypical HigB-HigA toxin-antitoxin system from Proteus vulgaris.

ABSTRACT: Bacterial toxin-antitoxin (TA) pairs transcriptionally autoregulate their expression via a repression/derepression mechanism in response to changing environmental conditions. The structural diversity of TA systems influences the mechanisms of transcriptional regulation. Here, we define the molecular mechanism for the plasmid-encoded HigB-HigA TA pair originally identified in a post-operative infection with antibiotic-resistant Proteus vulgaris. We determine DNA binding and promoter activity by the HigB-HigA complex supported by structural biology and molecular dynamics simulations of an elusive DNA operator-TA repressor complex. To define the optimal oligomeric TA repressor-DNA operator complex required for derepression, we engineered a dedicated trimeric HigB-HigA2 complex that represses

SUBMITTER: Pavelich IJ 

PROVIDER: S-EPMC12266136 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature