1foq

Publication Abstract from PubMed

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.

Structure of the bacteriophage phi29 DNA packaging motor.,Simpson AA, Tao Y, Leiman PG, Badasso MO, He Y, Jardine PJ, Olson NH, Morais MC, Grimes S, Anderson DL, Baker TS, Rossmann MG Nature. 2000 Dec 7;408(6813):745-50. PMID:11130079^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.