Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Many viruses package their genome into preformed capsids using packaging motors powered by the hydrolysis of ATP. The hexameric ATPase P4 of dsRNA bacteriophage phi12, located at the vertices of the icosahedral capsid, is such a packaging motor. We have captured crystallographic structures of P4 for all the key points along the catalytic pathway, including apo, substrate analog bound, and product bound. Substrate and product binding have been observed as both binary complexes and ternary complexes with divalent cations. These structures reveal large movements of the putative RNA binding loop, which are coupled with nucleotide binding and hydrolysis, indicating how ATP hydrolysis drives RNA translocation through cooperative conformational changes. Two distinct conformations of bound nucleotide triphosphate suggest how hydrolysis is activated by RNA binding. This provides a model for chemomechanical coupling for a prototype of the large family of hexameric helicases and oligonucleotide translocating enzymes.

Original publication

DOI

10.1016/j.cell.2004.09.007

Type

Journal article

Journal

Cell

Publication Date

17/09/2004

Volume

118

Pages

743 - 755

Keywords

Adenosine Triphosphatases, Adenosine Triphosphate, Amino Acid Sequence, Binding Sites, Capsid, Crystallography, X-Ray, Escherichia coli, Hydrolysis, Macromolecular Substances, Models, Molecular, Molecular Motor Proteins, Molecular Sequence Data, Protein Conformation, RNA, RNA Transport, RNA, Double-Stranded, RNA, Viral, Transcription Factors, Viral Proteins