Three-dimensional structure of bacteriophage T4 baseplate.
The baseplate of bacteriophage T4 is a multiprotein molecular machine that controls host cell recognition, attachment, tail sheath contraction and viral DNA ejection. We report here the three-dimensional structure of the baseplate-tail tube complex determined to a resolution of 12 A by cryoelectron microscopy. The baseplate has a six-fold symmetric, dome-like structure approximately 520 A in diameter and approximately 270 A long, assembled around a central hub. A 940 A-long and 96 A-diameter tail tube, coaxial with the hub, is connected to the top of the baseplate. At the center of the dome is a needle-like structure that was previously identified as a cell puncturing device. We have identified the locations of six proteins with known atomic structures, and established the position and shape of several other baseplate proteins. The baseplate structure suggests a mechanism of baseplate triggering and structural transition during the initial stages of T4 infection.
Kostyuchenko
Victor A
VA
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Sciences, 16/10 Miklukho-Maklaya Str., 117997 Moscow, Russia.
Leiman
Petr G
PG
Chipman
Paul R
PR
Kanamaru
Shuji
S
van Raaij
Mark J
MJ
Arisaka
Fumio
F
Mesyanzhinov
Vadim V
VV
Rossmann
Michael G
MG
D017122:Bacteriophage T4 / Q000737:chemistry* / Q000648:ultrastructure; D020285:Cryoelectron Microscopy; D007091:Image Processing, Computer-Assisted; D008854:Microscopy, Electron; D008958:Models, Molecular; D017434:Protein Structure, Tertiary