Type VI secretion system effector, Hcp; HCP is a family of proteins which are expressed in up to 1000 copies in Gram-negative bacteria. Together these copies aggregate into a needle-like shaft or tube that will penetrate other bacteria via a puncturing protein attached to its head. Initially Hcp forms a hexameric structure with a central channel of 40 Angstroms. These hexamers pile up one on top of each other forming nanotubes resembling the gp19 tail phage tube.

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2507059      1 ATPAYMSITGTKQGLITAGAFTADSVGNTYQEGFEDQVMVQGFDPAVIIPTGPVYGQ 57
Cdd:TIGR03344   1 ANPIYLTITGKTQGLISAGCSTADSIGNKYQEGHEDEIMVLAFDHSISRPQNPQSGL 57

type VI secretion system effector, Hcp1 family; This family includes Hcp1 (hemolysin coregulated protein 1), an exported, homohexameric ring-forming virulence protein from Pseudomonas aeruginosa. Hcp1 lacks a conventional signal sequence and is instead exported by means of the type VI secretion system, encoded by a pathogenicity cluster of a class previously designated IAHP (IcmF-associated homologous protein). Homologs of Hcp1, in this protein family, are found in various bacteria of which most but not all are known pathogens. Pathogens may have many multiple members of this family, with three to ten in Erwinia carotovora, Yersinia pestis, uropathogenic Escherichia coli, and the insect pathogen Photorhabdus luminescens. [Cellular processes, Pathogenesis]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2507059      1 ATPAYMSITGTKQGLITAGAFTADSVGNTYQEGFEDQVMVQGFDPAVIIPTGPVYGQ 57
Cdd:TIGR03344   1 ANPIYLTITGKTQGLISAGCSTADSIGNKYQEGHEDEIMVLAFDHSISRPQNPQSGL 57

type VI secretion system effector, Hcp1 family; This family includes Hcp1 (hemolysin coregulated protein 1), an exported, homohexameric ring-forming virulence protein from Pseudomonas aeruginosa. Hcp1 lacks a conventional signal sequence and is instead exported by means of the type VI secretion system, encoded by a pathogenicity cluster of a class previously designated IAHP (IcmF-associated homologous protein). Homologs of Hcp1, in this protein family, are found in various bacteria of which most but not all are known pathogens. Pathogens may have many multiple members of this family, with three to ten in Erwinia carotovora, Yersinia pestis, uropathogenic Escherichia coli, and the insect pathogen Photorhabdus luminescens. [Cellular processes, Pathogenesis]

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 2507059      1 ATPAYMSITGTKQGLITAGAFTADSVGNTYQEGFEDQVMVQGFDPAVIIPTGPVYGQ 57
Cdd:TIGR03344   1 ANPIYLTITGKTQGLISAGCSTADSIGNKYQEGHEDEIMVLAFDHSISRPQNPQSGL 57