Structure of the bacteriophage phi29 DNA packaging motor.
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.
Simpson
A A
AA
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907-1392, USA.
Tao
Y
Y
Leiman
P G
PG
Badasso
M O
MO
He
Y
Y
Jardine
P J
PJ
Olson
N H
NH
Morais
M C
MC
Grimes
S
S
Anderson
D L
DL
Baker
T S
TS
Rossmann
M G
MG
D000251:Adenosine Triphosphatases / Q000737:chemistry; D017103:Bacillus Phages / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002213:Capsid / Q000737:chemistry / Q000378:metabolism; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D004279:DNA, Viral / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000378:metabolism; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry
D004279:DNA, Viral; D020409:Molecular Motor Proteins; D012367:RNA, Viral; D000251:Adenosine Triphosphatases