Structure of the bacteriophage phi29 DNA packaging motor

• Published in: Nature (London) Vol. 408; no. 6813; pp. 745 - 750
• Main Authors: Simpson, A A, Tao, Y, Leiman, P G, Badasso, M O, He, Y, Jardine, P J, Olson, N H, Morais, M C, Grimes, S, Anderson, D L, Baker, T S, Rossmann, M G
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 07.12.2000
• Subjects: Adenosine Triphosphatases - chemistry; ATP; Bacillus Phages - chemistry; Bacillus Phages - genetics; Bacillus Phages - metabolism; Bacteria; Capsid - chemistry; Capsid - metabolism; Cryoelectron Microscopy; Crystallography; Crystallography, X-Ray; Deoxyribonucleic acid; DNA; DNA, Viral - chemistry; DNA, Viral - metabolism; Hydrolysis; Microbiology; Models, Molecular; Molecular Motor Proteins - chemistry; Molecular Motor Proteins - metabolism; Nucleic Acid Conformation; Packaging; Ribonucleic acid; RNA; RNA, Viral - chemistry; Viruses
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/35047129

Motors generating mechanical force, powered by the hydrolysis of ATP, translocate double-stranded DNA into preformed capsids (proheads) of bacterial viruses and certain animal viruses. Here we describe the motor that packages the double-stranded DNA of the Bacillus subtilis bacteriophage phi29 into a precursor capsid. We determined the structure of the head-tail connector--the central component of the phi29 DNA packaging motor--to 3.2 A resolution by means of X-ray crystallography. We then fitted the connector into the electron densities of the prohead and of the partially packaged prohead as determined using cryo-electron microscopy and image reconstruction analysis. Our results suggest that the prohead plus dodecameric connector, prohead RNA, viral ATPase and DNA comprise a rotary motor with the head-prohead RNA-ATPase complex acting as a stator, the DNA acting as a spindle, and the connector as a ball-race. The helical nature of the DNA converts the rotary action of the connector into translation of the DNA.