Structural insights into the unique mechanism of transcription activation by Caulobacter crescentus GcrA.

ABSTRACT: Canonical bacterial transcription activators bind to non-transcribed promoter elements to increase transcription of their target genes. Here we report crystal structures of binary complexes comprising domains of Caulobacter crescentus GcrA, a noncanonical bacterial transcription factor, that support a novel mechanism for transcription activation through the preferential binding of methylated cis-regulatory elements and the promotion of open complex formation through an interaction with region 2 of the principal σ factor, σ70. We present crystal structures of the C-terminal, σ factor-interacting domain (GcrA-SID) in complex with domain 2 of σ70 (σ702), and the N-terminal, DNA-binding domain (GcrA-DBD) in complex with methylated double-stranded DNA (dsDNA). The structures reveal interactions

SUBMITTER: Wu X 

PROVIDER: S-EPMC5887438 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature