5YIX

Caulobacter crescentus GcrA sigma-interacting domain (SID) in complex with domain 2 of sigma 70

Summary for 5YIX

• Entry DOI: 10.2210/pdb5yix/pdb
• Descriptor: RNA polymerase sigma factor RpoD, Cell cycle regulatory protein GcrA, (R,R)-2,3-BUTANEDIOL, ... (5 entities in total)
• Functional Keywords: caulobacter crescentus, gcra, sigma-interacting domain, transcription factor, dna binding protein
• Biological source: Caulobacter crescentus (strain NA1000 / CB15N); More
• Cellular location: Cytoplasm : A0A0H3CAV3
• Total number of polymer chains: 2
• Total formula weight: 50068.87

Authors

Wu, X.,Zhang, Y. (deposition date: 2017-10-06, release date: 2018-03-21, Last modification date: 2024-03-27)

Primary citation

Wu, X.,Haakonsen, D.L.,Sanderlin, A.G.,Liu, Y.J.,Shen, L.,Zhuang, N.,Laub, M.T.,Zhang, Y.
Structural insights into the unique mechanism of transcription activation by Caulobacter crescentus GcrA.
Nucleic Acids Res., 46:3245-3256, 2018

PubMed 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 essential for transcription activation and DNA recognition by GcrA. These structures, along with mutational analyses, support a mechanism of transcription activation in which GcrA associates with RNA polymerase (RNAP) prior to promoter binding through GcrA-SID, arming RNAP with a flexible GcrA-DBD. The RNAP-GcrA complex then binds and activates target promoters harboring a methylated GcrA binding site either upstream or downstream of the transcription start site.

PubMed: 29514271
DOI: 10.1093/nar/gky161

Experimental method

X-RAY DIFFRACTION (2.302 Å)