Summary information and primary citation

5vi5; DSSR-derived features in text and JSON formats
X-ray (3.196 Å)
Structure of mycobacterium smegmatis transcription initiation complex with a full transcription bubble
Hubin EA, Lilic M, Darst SA, Campbell EA (2017): "Structural insights into the mycobacteria transcription initiation complex from analysis of X-ray crystal structures." Nat Commun, 8, 16072. doi: 10.1038/ncomms16072.
The mycobacteria RNA polymerase (RNAP) is a target for antimicrobials against tuberculosis, motivating structure/function studies. Here we report a 3.2 Å-resolution crystal structure of a Mycobacterium smegmatis (Msm) open promoter complex (RPo), along with structural analysis of the Msm RPo and a previously reported 2.76 Å-resolution crystal structure of an Msm transcription initiation complex with a promoter DNA fragment. We observe the interaction of the Msm RNAP α-subunit C-terminal domain (αCTD) with DNA, and we provide evidence that the αCTD may play a role in Mtb transcription regulation. Our results reveal the structure of an Actinobacteria-unique insert of the RNAP β' subunit. Finally, our analysis reveals the disposition of the N-terminal segment of Msm σ(A), which may comprise an intrinsically disordered protein domain unique to mycobacteria. The clade-specific features of the mycobacteria RNAP provide clues to the profound instability of mycobacteria RPo compared with E. coli.

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