Repression of Acinetobacter baumannii DNA damage response requires DdrR-assisted binding of UmuDAb dimers to atypical SOS box.

ABSTRACT: The DNA damage response of the multi-drug-resistant nosocomial pathogen Acinetobacter baumannii possesses multiple features that distinguish it from the commonly used LexA repression system. These include the absence of LexA in this genus, the evolution of a UmuD polymerase manager into the UmuDAb repressor of error-prone polymerases, the use of a corepressor unique to Acinetobacter (DdrR), and an unusually large UmuDAb binding site. We defined cis- and trans-acting factors required for UmuDAb DNA binding and gene repression, and tested whether DdrR directly enhances its DNA binding. We used DNA binding assays to characterize UmuDAb's binding to its proposed operator present upstream of the six co-repressed umuDC or umuC genes. UmuDAb bound tightly and cooperati

SUBMITTER: Candra B 

PROVIDER: S-EPMC11332147 | biostudies-literature | 2024 Jun

REPOSITORIES: biostudies-literature