This family of proteins includes Gp5 from bacteriophage P22 and related proteins. Gp5 is involved in the formation of the pro-capsid shells in the bacteriophage. In total, there are 415 molecules of the coat protein which are arranged in an icosahedral shell [].
Arterivirus such as porcine reproductive and respiratory syndrome virus (PRRSV) contain four glycoproteins on the virion envelope: the major glycoprotein GP5 and minor glycoproteins GP2a, GP3, and GP4. GP5, previously known as Gl, is encoded in ORF5 and is 30- 45kDa in size []. Gl is heterogeneously glycosylated with N-acetyllactosamine in a cell-type-specific manner. It is the most abundant envelope glycoprotein and a key target for neutralising antibodies [, ].
This entry includes the pre-baseplate central spike protein Gp5 from bacteriophage T4 which is a baseplate central spike complex-associated lysozyme, essential for the localized hydrolysis of bacterial cell wall. This allows the tail tube to penetrate to the host inner membrane, through which the phage DNA is ejected [, , , ].
This superfamily represents the P5 murein endopeptidase from Pseudomonas phage phi6. P5 murein endopeptidase has lytic activity against several Gram-negative bacteria []. It is thought that the enzyme cleaves the cell wall peptide bridge formed by meso-2,6-diaminopimelic acid and D-Alanine.
This domain is found at the N terminus of the Gp5 baseplate protein of Bacteriophage T4. The baseplate is located at the end of the phage tail. Gp5 is a lysozyme essential for localised hydrolysis of bacterial cell wall, which is necessary for viral DNA injection []. This domain binds to the Gp27 protein []. It has the common OB fold [].
Equine arteritis virus (EAV) is an enveloped, positive-strand RNA virus belonging to the family Arteriviridae. EAV virions contain six different envelope proteins. GP5 (previously named GL) and the unglycosylated membrane protein M are the major envelope proteins, while the glycoproteins GP2b (previously named Gs), GP3, and GP4 are minor structural proteins []. GP2b is a class I transmembrane protein which adopts a number of different conformations [, ].
This domain occurs in a family of phage (and bacteriocin) proteins related to the phage P2 V gene product, which forms the small spike at the tip of the tail []. Homologs in general are annotated as baseplate assembly protein V. At least one member is encoded within a region of Pectobacterium carotovorum (Erwinia carotovora) described as a bacteriocin, a phage tail-derived module able to kill bacteria closely related to the host strain.It is also found in Vgr-related proteins. Genes encoding type VI secretion systems (T6SS) are widely distributed in pathogenic Gram-negative bacterial species. In Vibrio cholerae, T6SS have been found to secrete three related proteins extracellularly, VgrG-1, VgrG-2, and VgrG-3. VgrG-1 can covalently cross-link actin in vitro, and this activity was used to demonstrate that V. cholerae can translocate VgrG-1 into macrophages by a T6SS-dependent mechanism. VgrG-related proteins likely assemble into a trimeric complex that is analogous to that formed by the two trimeric proteins gp27 and gp5 that make up the baseplate "tail spike"of Escherichia coli bacteriophage T4. The VgrG components of the T6SS apparatus might assemble a "cell-puncturing device"analogous to phage tail spikes to deliver effector protein domains through membranes of target host cells [].Gp5 is an integral component of the virion baseplate of bacteriophage T4. T4 Gp5 consists of 3 domains connected via long linkers: the N-terminal oligosaccharide/oligonucleotide-binding (OB)-fold domain, the middle lysozyme domain, and the C-terminal triplestranded-helix. The equivalent of the Gp5 OB-fold domain in the structure of VgrG is the domain of unknown function comprising residues 380-470 and conserved in all known VgrGs. This entry represents the OB-fold domain which consists of a 5-stranded antiparallel-barrel with a Greek-key topology [].
This domain occurs in a family of phage (and bacteriocin) proteins related to the phage P2 V gene product, which forms the small spike at the tip of the tail []. Homologs in general are annotated as baseplate assembly protein V. At least one member is encoded within a region of Pectobacterium carotovorum (Erwinia carotovora) described as a bacteriocin, a phage tail-derived module able to kill bacteria closely related to the host strain.It is also found in Vgr-related proteins. Genes encoding type VI secretion systems (T6SS) are widely distributed in pathogenic Gram-negative bacterial species. In Vibrio cholerae, T6SS have been found to secrete three related proteins extracellularly, VgrG-1, VgrG-2, and VgrG-3. VgrG-1 can covalently cross-link actin in vitro, and this activity was used to demonstrate that V. cholerae can translocate VgrG-1 into macrophages by a T6SS-dependent mechanism. VgrG-related proteins likely assemble into a trimeric complex that is analogous to that formed by the two trimeric proteins gp27 and gp5 that make up the baseplate "tail spike"of Escherichia coli bacteriophage T4. The VgrG components of the T6SS apparatus might assemble a "cell-puncturing device"analogous to phage tail spikes to deliver effector protein domains through membranes of target host cells [].Gp5 is an integral component of the virion baseplate of bacteriophage T4. T4 Gp5 consists of 3 domains connected via long linkers: the N-terminal oligosaccharide/oligonucleotide-binding (OB)-fold domain, the middle lysozyme domain, and the C-terminal triplestranded-helix. The equivalent of the Gp5 OB-fold domain in the structure of VgrG is the domain of unknown function comprising residues 380-470 and conserved in all known VgrGs. This entry represents the OB-fold domain which consists of a 5-stranded antiparallel-barrel with a Greek-key topology [].
