Structural and Molecular Basis for Coordination in a Viral DNA Packaging Motor.
Mao, H., Saha, M., Reyes-Aldrete, E., Sherman, M.B., Woodson, M., Atz, R., Grimes, S., Jardine, P.J., Morais, M.C.(2016) Cell Rep 14: 2017-2029
- PubMed: 26904950 
- DOI: https://doi.org/10.1016/j.celrep.2016.01.058
- Primary Citation of Related Structures:  
5HD9 - PubMed Abstract: 
Ring NTPases are a class of ubiquitous molecular motors involved in basic biological partitioning processes. dsDNA viruses encode ring ATPases that translocate their genomes to near-crystalline densities within pre-assembled viral capsids. Here, X-ray crystallography, cryoEM, and biochemical analyses of the dsDNA packaging motor in bacteriophage phi29 show how individual subunits are arranged in a pentameric ATPase ring and suggest how their activities are coordinated to translocate dsDNA. The resulting pseudo-atomic structure of the motor and accompanying functional analyses show how ATP is bound in the ATPase active site; identify two DNA contacts, including a potential DNA translocating loop; demonstrate that a trans-acting arginine finger is involved in coordinating hydrolysis around the ring; and suggest a functional coupling between the arginine finger and the DNA translocating loop. The ability to visualize the motor in action illuminates how the different motor components interact with each other and with their DNA substrate.
Organizational Affiliation: 
Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA.