TY - JOUR
T1 - Cryo-EM structure of Escherichia coli 70 RNA polymerase and promoter DNA complex revealed a role of non-conserved region during the open complex formation
AU - Narayanan, Anoop
AU - Vago, Frank S.
AU - Li, Kunpeng
AU - Qayyum, M. Zuhaib
AU - Yernool, Dinesh
AU - Jiang, Wen
AU - Murakami, Katsuhiko S.
N1 - Funding Information:
This work was supported by National Institutes of Health Grants GM087350 (to K. S. M.) and GM093142 (to D. Y.). The authors declare that they have no conflicts of interest with the contents of this article. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This article contains Figs. S1–S5 and Movie S1. The atomic coordinates and structure factors (codes 6C9Y and 6CA0) have been deposited in the Protein Data Bank (http://wwpdb.org/). 1 These authors contributed equally to this work. 2To whom correspondence may be addressed. Tel.: 765-496-8436; E-mail: jiang12@purdue.edu. 3To whom correspondence may be addressed. Tel.: 814-865-2758; E-mail: kum14@psu.edu. 4 The abbreviations used are: RNAP, RNA polymerase; σNCR, σ non-conserved region; nt-DNA, non-template DNA; t-DNA, template DNA; TIC, transcrip-tion initiation complex; DME, downstream mobile element; 2-AP, 2-amino-purine; MTB, Mycobacterium tuberculosis.
Publisher Copyright:
© 2018 Narayanan et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2018/5/11
Y1 - 2018/5/11
N2 - First step of gene expression is transcribing the genetic information stored in DNA to RNA by the transcription machinery including RNA polymerase (RNAP). In Escherichia coli, a primary70 factor forms the RNAP holoenzyme to express housekeeping genes. The 70 contains a large insertion between the conserved regions 1.2 and 2.1, the non-conserved region (NCR), but its function remains to be elucidated. In this study, we determined the cryo-EM structures of the E. coli RNAP70 holoenzyme and its complex with promoter DNA (open complex, RPo) at 4.2 and 5.75 Å resolutions, respectively, to reveal native conformations of RNAP and DNA. The RPo structure presented here found an interaction between theNCR and promoter DNA just upstream of the 10 element, which was not observed in a previously determined E. coli RNAP transcription initiation complex (RPo plus short RNA) structure by X-ray crystallography because of restraint of crystal packing effects. Disruption of theNCR and DNA interaction by the amino acid substitutions (R157A/R157E) influences the DNA opening around the transcription start site and therefore decreases the transcription activity of RNAP. We propose that the NCR and DNA interaction is conserved in proteobacteria, and RNAP in other bacteria replaces its role with a transcription factor.
AB - First step of gene expression is transcribing the genetic information stored in DNA to RNA by the transcription machinery including RNA polymerase (RNAP). In Escherichia coli, a primary70 factor forms the RNAP holoenzyme to express housekeeping genes. The 70 contains a large insertion between the conserved regions 1.2 and 2.1, the non-conserved region (NCR), but its function remains to be elucidated. In this study, we determined the cryo-EM structures of the E. coli RNAP70 holoenzyme and its complex with promoter DNA (open complex, RPo) at 4.2 and 5.75 Å resolutions, respectively, to reveal native conformations of RNAP and DNA. The RPo structure presented here found an interaction between theNCR and promoter DNA just upstream of the 10 element, which was not observed in a previously determined E. coli RNAP transcription initiation complex (RPo plus short RNA) structure by X-ray crystallography because of restraint of crystal packing effects. Disruption of theNCR and DNA interaction by the amino acid substitutions (R157A/R157E) influences the DNA opening around the transcription start site and therefore decreases the transcription activity of RNAP. We propose that the NCR and DNA interaction is conserved in proteobacteria, and RNAP in other bacteria replaces its role with a transcription factor.
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U2 - 10.1074/jbc.RA118.002161
DO - 10.1074/jbc.RA118.002161
M3 - Article
C2 - 29581236
AN - SCOPUS:85046956777
VL - 293
SP - 7367
EP - 7375
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 19
ER -