Three-dimensional structure of bacteriophage T4 baseplate

Nat Struct Biol. 2003 Sep;10(9):688-93. doi: 10.1038/nsb970. Epub 2003 Aug 17.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Bacteriophage T4 / chemistry*
  • Bacteriophage T4 / ultrastructure
  • Cryoelectron Microscopy
  • Image Processing, Computer-Assisted
  • Microscopy, Electron
  • Models, Molecular
  • Protein Structure, Tertiary

Associated data

  • PDB/1PDF
  • PDB/1PDI
  • PDB/1PDJ
  • PDB/1PDL
  • PDB/1PDM
  • PDB/1PDP