2poh | pdb_00002poh
Structure of Phage P22 Tail Needle gp26
Structural highlights
FunctionNEEDL_BPP22 Cell-perforating component and plug protein of the phage tail machine. Host cell membrane perforation allows viral DNA ejection. Together with gp4 and gp10, gp26 is required for stabilization of the condensed DNA within the capsid by plugging the hole through which the DNA enters.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedBacteriophage P22 infects Salmonella enterica by injecting its genetic material through the cell envelope. During infection, a specialized tail needle, gp26, is injected into the host, likely piercing a hole in the host cell envelope. The 2.1-A crystal structure of gp26 reveals a 240-A elongated protein fiber formed by two trimeric coiled-coil domains interrupted by a triple beta-helix. The N terminus of gp26 plugs the portal protein channel, retaining the genetic material inside the virion. The C-terminal tip of the fiber exposes beta-hairpins with hydrophobic tips similar to those seen in class II fusion peptides. The alpha-helical core connecting these two functionally polarized tips presents four trimerization octads with consensus sequence IXXLXXXV. The slender conformation of the gp26 fiber minimizes the surface exposed to solvent, which is consistent with the idea that gp26 traverses the cell envelope lipid bilayers. Structure of phage P22 cell envelope-penetrating needle.,Olia AS, Casjens S, Cingolani G Nat Struct Mol Biol. 2007 Dec 2. PMID:18059287[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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