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Publication Abstract from PubMed

The NtrC-like AAA+ ATPases control virulence and other important bacterial activities through delivering mechanical work to sigma54-RNA polymerase to activate transcription from sigma54-dependent genes. We report the first crystal structure for such an ATPase, NtrC1 of Aquifex aeolicus, in which the catalytic arginine engages the gamma-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 sigma54. Second, ATP hydrolysis permits Pi release and retraction of the arginine with a reversed roll, remodeling sigma54-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.

Engagement of arginine finger to ATP triggers large conformational changes in NtrC1 AAA+ ATPase for remodeling bacterial RNA polymerase.,Chen B, Sysoeva TA, Chowdhury S, Guo L, De Carlo S, Hanson JA, Yang H, Nixon BT Structure. 2010 Nov 10;18(11):1420-30. PMID:21070941^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.