Structural highlights
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Function
[PORTL_BPP22] Required for successful condensation of DNA within the capsid. Gp1 is a minor structural protein. The portal protein is present as a single ring-shaped dodecamer located at the point where tails attach. It is through this ring that DNA is thought to enter the prohead. [FIBER_BPP22] Structural component of the short non-contractile tail. The tail comprises six fibers that mediate primary attachment to the host cell lipopolysaccharides (LPS) and display endorhamnosidase enzymatic activity, hydrolyzing the alpha-1,3-O-glycosidic linkage between rhamnose and galactose of the O-antigen polysaccharide. Digestion of the LPS brings the capsid near the cell outer membrane.[1] [2] [EXLYS_BPP22] Tail protein located at the vertex occupied by the portal ring. Together with gp10 and gp26, gp4 is required for stabilization of the condensed DNA within the capsid; perhaps by plugging the hole through which the DNA enters. Plays a role in ejection of the bacteriophage DNA into the host cell at the initiation of infection. Functions as an exolysin that catalyzes the cleavage of the glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine residues in peptidoglycans.[3]
References
- ↑ Weigele PR, Scanlon E, King J. Homotrimeric, beta-stranded viral adhesins and tail proteins. J Bacteriol. 2003 Jul;185(14):4022-30. PMID:12837775
- ↑ Andres D, Hanke C, Baxa U, Seul A, Barbirz S, Seckler R. Tailspike interactions with lipopolysaccharide effect DNA ejection from phage P22 particles in vitro. J Biol Chem. 2010 Nov 19;285(47):36768-75. doi: 10.1074/jbc.M110.169003. Epub, 2010 Sep 3. PMID:20817910 doi:http://dx.doi.org/10.1074/jbc.M110.169003
- ↑ Moak M, Molineux IJ. Peptidoglycan hydrolytic activities associated with bacteriophage virions. Mol Microbiol. 2004 Feb;51(4):1169-83. PMID:14763988
