title: Three-dimensional structure of bacteriophage T4 baseplate.
abstract: 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.
authors.affiliation: Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of Russian Academy of Sciences, 16/10 Miklukho-Maklaya Str., 117997 Moscow, Russia.
authors.forename: Victor A
authors.initials: VA
authors.lastname: Kostyuchenko
authors.forename: Petr G
authors.initials: PG
authors.lastname: Leiman
authors.forename: Paul R
authors.initials: PR
authors.lastname: Chipman
authors.forename: Shuji
authors.initials: S
authors.lastname: Kanamaru
authors.forename: Mark J
authors.initials: MJ
authors.lastname: van Raaij
authors.forename: Fumio
authors.initials: F
authors.lastname: Arisaka
authors.forename: Vadim V
authors.initials: VV
authors.lastname: Mesyanzhinov
authors.forename: Michael G
authors.initials: MG
authors.lastname: Rossmann
mesh_terms: 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