Engagement of arginine finger to ATP triggers large conformational changes in NtrC1 AAA+ ATPase for remodeling bacterial RNA polymerase.
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.
Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA.
Baoyu
B
Chen
Tatyana A
TA
Sysoeva
Saikat
S
Chowdhury
Liang
L
Guo
Sacha
S
De Carlo
Jeffrey A
JA
Hanson
Haw
H
Yang
B Tracy
BT
Nixon
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001120:Arginine / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D006868:Hydrolysis; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D011487:Protein Conformation; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D014157:Transcription Factors; D000255:Adenosine Triphosphate; D001120:Arginine; D012321:DNA-Directed RNA Polymerases; D000251:Adenosine Triphosphatases