8IGR

Cryo-EM structure of CII-dependent transcription activation complex

Summary for 8IGR

• Entry DOI: 10.2210/pdb8igr/pdb
• EMDB information: 35438
• Descriptor: DNA-directed RNA polymerase subunit alpha, ZINC ION, DNA-directed RNA polymerase subunit beta, ... (10 entities in total)
• Functional Keywords: rna polymerase, transcription, transcription activation, bacteriophage, cii
• Biological source: Escherichia coli (strain K12); More
• Total number of polymer chains: 12
• Total formula weight: 556775.21

Authors

Zhao, M.,Gao, B.,Wen, A.,Feng, Y.,Lu, Y. (deposition date: 2023-02-21, release date: 2023-05-17, Last modification date: 2023-08-16)

Primary citation

Zhao, M.,Gao, B.,Wen, A.,Feng, Y.,Lu, Y.Q.
Structural basis of lambda CII-dependent transcription activation.
Structure, 31:968-, 2023

PubMed Abstract: The CII protein of bacteriophage λ activates transcription from the phage promoters P, P, and P by binding to two direct repeats that straddle the promoter -35 element. Although genetic, biochemical, and structural studies have elucidated many aspects of λCII-mediated transcription activation, no precise structure of the transcription machinery in the process is available. Here, we report a 3.1-Å cryo-electron microscopy (cryo-EM) structure of an intact λCII-dependent transcription activation complex (TAC-λCII), which comprises λCII, E. coli RNAP-σ holoenzyme, and the phage promoter P. The structure reveals the interactions between λCII and the direct repeats responsible for promoter specificity and the interactions between λCII and RNAP α subunit C-terminal domain responsible for transcription activation. We also determined a 3.4-Å cryo-EM structure of an RNAP-promoter open complex (RPo-P) from the same dataset. Structural comparison between TAC-λCII and RPo-P provides new insights into λCII-dependent transcription activation.

PubMed: 37269829
DOI: 10.1016/j.str.2023.05.008

Experimental method

ELECTRON MICROSCOPY (3.1 Å)