Protein Domain : Bacteriophage SPP1, head-tail adaptor superfamily IPR038666

Type	Homologous_superfamily
Description	This entry describes the head-tail adaptor protein of bacteriophage SPP1 and related proteins in other bacteriophage and prophage regions of bacterial genomes. Homologues are also found in Gene Transfer Agents (GTA) [], including ORFg7 (RCAP_rcc01689) of the GTA of Rhodobacter capsulatus (Rhodopseudomonas capsulata) [].In bacteriophage SPP1, the gp16 protein functions as a stopper, locking the viral DNA into the capsid. When the tail attachment binds to the entry receptor, gp16 opens by a diaphragm-like motion, allowing the genome to exit the capsid through the tail tube to the host cell. During virion assembly, gp16 functions as a docking platform to which the preassembled tail binds [ ].The SPP1 head-to-tail connector is composed of cyclical dodecamers of the portal protein gp6 and of the 2 head completion proteins gp15 and gp16 [].
Short Name	SSP1_head-tail_sf