Engagement of Arginine Finger to ATP Triggers Large Conformational Changes in NtrC1 AAA+ ATPase for Remodeling Bacterial RNA Polymerase

Baoyu Chen, Tatyana A. Sysoeva, Saikat Chowdhury, Liang Guo, Sacha De Carlo, Jeffrey A. Hanson, Haw Yang, B. Tracy Nixon

Research output: Contribution to journalArticle

35 Scopus citations


The NtrC-like AAA+ ATPases control virulence and other important bacterial activities through delivering mechanical work to σ54-RNA polymerase to activate transcription from σ54-dependent genes. We report the first crystal structure for such an ATPase, NtrC1 of Aquifex aeolicus, in which the catalytic arginine engages the γ-phosphate of ATP. Comparing the new structure with those previously known for apo and ADP-bound states supports a rigid-body displacement model that is consistent with large-scale conformational changes observed by low-resolution methods. First, the arginine finger induces rigid-body roll, extending surface loops above the plane of the ATPase ring to bind σ54. Second, ATP hydrolysis permits Pi release and retraction of the arginine with a reversed roll, remodeling σ54-RNAP. This model provides a fresh perspective on how ATPase subunits interact within the ring-ensemble to promote transcription, directing attention to structural changes on the arginine-finger side of an ATP-bound interface.

Original languageEnglish (US)
Pages (from-to)1420-1430
Number of pages11
Issue number11
Publication statusPublished - Nov 10 2010


All Science Journal Classification (ASJC) codes

  • Structural Biology
  • Molecular Biology

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