2c3f: Difference between revisions
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==Overview== | ==Overview== | ||
Streptococcus pyogenes (group A Streptococcus) causes severe invasive, infections including scarlet fever, pharyngitis (streptococcal sore, throat), skin infections, necrotizing fasciitis (flesh-eating disease), septicemia, erysipelas, cellulitis, acute rheumatic fever, and toxic, shock. The conversion from nonpathogenic to toxigenic strains of S., pyogenes is frequently mediated by bacteriophage infection. One of the key, bacteriophage-encoded virulence factors is a putative "hyaluronidase,", HylP1, a phage tail-fiber protein responsible for the digestion of the S., pyogenes hyaluronan capsule during phage infection. Here we demonstrate, that HylP1 is a hyaluronate lyase. The 3D structure, at 1.8-angstroms, resolution, reveals an unusual triple-stranded beta-helical structure and, ... | Streptococcus pyogenes (group A Streptococcus) causes severe invasive, infections including scarlet fever, pharyngitis (streptococcal sore, throat), skin infections, necrotizing fasciitis (flesh-eating disease), septicemia, erysipelas, cellulitis, acute rheumatic fever, and toxic, shock. The conversion from nonpathogenic to toxigenic strains of S., pyogenes is frequently mediated by bacteriophage infection. One of the key, bacteriophage-encoded virulence factors is a putative "hyaluronidase,", HylP1, a phage tail-fiber protein responsible for the digestion of the S., pyogenes hyaluronan capsule during phage infection. Here we demonstrate, that HylP1 is a hyaluronate lyase. The 3D structure, at 1.8-angstroms, resolution, reveals an unusual triple-stranded beta-helical structure and, provides insight into the structural basis for phage tail assembly and the, role of phage tail proteins in virulence. Unlike the triple-stranded, beta-helix assemblies of the bacteriophage T4 injection machinery and the, tailspike endosialidase of the Escherichia coli K1 bacteriophage K1F, HylP1 possesses three copies of the active center on the triple-helical, fiber itself without the need for an accessory catalytic domain. The, triple-stranded beta-helix is not simply a structural scaffold, as, previously envisaged; it is harnessed to provide a 200-angstroms-long, substrate-binding groove for the optimal reduction in hyaluronan viscosity, to aid phage penetration of the capsule. | ||
==About this Structure== | ==About this Structure== | ||
2C3F is a | 2C3F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptococcus_pyogenes Streptococcus pyogenes] with NA as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Hyaluronate_lyase Hyaluronate lyase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.2.1 4.2.2.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2C3F OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: triple-stranded beta-helix]] | [[Category: triple-stranded beta-helix]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:48:45 2007'' | ||
