Biochemistry and Molecular Biology
Penn State Science
You are here: Home News 2010 News Snapshot of a Molecular Motor

Snapshot of a Molecular Motor

Main Content

Filed under:

Stucture Magazine Cover-Tracy NixonBMB researcher Tracy Nixon and colleagues determined the first crystal structure of a bacterial enhancer binding protein (bEBP) bound by ATP.  bEBPs, which form a subset of the ubiquitous AAA+ ATPases, are activators that channel the energy of ATP binding and hydrolysis toward remodeling a protein factor called σ54.  This spatially altered protein is believed to separate the double stands of bacterial DNA to allow for the transcription of σ54-dependent genes by σ54’s associated RNA polymerase.  By comparing with structure of the same bEBP bound by ADP, large scale conformational changes pre- and post- ATP hydrolysis were observed involving the arginine finger of the bEBP.  This finding contributes toward a better understanding of how ATP driven molecular motors work in cellular processes. 


Related Links

Engagement of Arginine Finger to ATP Triggers Large Conformational Changes in NtrC1 AAA+ ATPase for Remodeling Bacterial RNA Polymerase
B. Chen, T.A. Sysoeva, S. Chowdhury, L. Guo, S De Carlo, J.A. Hanson, H. Yang, B. T. Nixon. Structure.  2010 Nov 18(11): 1420-1430.

Search for Nixon BT in PubMEd for Tracy Nixon's Publications

 

bEBP at Work

Courtesy of Nixon Lab

Movie Legend: This movie begins with an overlay of ATP-bound and ADP-bound structures of bEBP ribbon (top) or space filling (bottom) models. The overlay then fades with the stereo images oscillating between the ATP- and ADP- bound structures. Hydrolysis of ATP releases its binding to the bEBP arginine finger (green) and causes a rotation between bEBP's two rigid components (white and blue) plus a movement of the flexible upper loops (top red) bound to σ54. The upper loop movement triggers mechanical work on σ54 for spatial modification and subsequent release.

Learn How To View This Movie in 3D 

Filed under: