3foa
From Proteopedia
Crystal structure of the bacteriophage T4 tail sheath protein, deletion mutant gp18M
Structural highlights
FunctionTSP_BPT4 Structural component of the bacteriophage tail which consists of a contractile sheath, a tube and a baseplate. The central cylindrical segment of the tail consists of a rigid tube, composed of multiple copies of gp19, surrounded by the outer contractile sheath assembled from gp18 subunits. A total of 138 copies of gp18 arranged into 23 hexameric rings constitutes the sheath. During infection, contraction of the sheath drives the central tube through the host outer membrane, creating a channel for DNA ejection from the capsid into the host cell.[1] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe contractile tail of bacteriophage T4 is a molecular machine that facilitates very high viral infection efficiency. Its major component is a tail sheath, which contracts during infection to less than half of its initial length. The sheath consists of 138 copies of the tail sheath protein, gene product (gp) 18, which surrounds the central non-contractile tail tube. The contraction of the sheath drives the tail tube through the outer membrane, creating a channel for the viral genome delivery. A crystal structure of about three quarters of gp18 has been determined and was fitted into cryo-electron microscopy reconstructions of the tail sheath before and after contraction. It was shown that during contraction, gp18 subunits slide over each other with no apparent change in their structure. The tail sheath structure of bacteriophage T4: a molecular machine for infecting bacteria.,Aksyuk AA, Leiman PG, Kurochkina LP, Shneider MM, Kostyuchenko VA, Mesyanzhinov VV, Rossmann MG EMBO J. 2009 Apr 8;28(7):821-9. Epub 2009 Feb 19. PMID:19229296[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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