proline-alanine-alanine-arginine (PAAR) domain with uncharacterized C-terminal extension; This domain is found in the PAAR (proline-alanine-alanine-arginine) repeat family of mostly beta- and gamma-proteobacteria, and forms a sharp conical extension on the VgrG spike, a trimeric protein complex of the bacterial type VI secretion system (T6SS). Most members contain C-terminal domain extensions corresponding to several uncharacterized domains such as S-type pyocin, DUF2235, DUF2345 and cytotoxic proteins. However, these terminal domains are exposed to solution, and do not distort the binding site of VgrG. The pointed tip of the PAAR domain is stabilized by a zinc atom positioned close to the cone's vertex and is likely to be important for its integrity during penetration of the target cell envelope. VgrG proteins are orthologous to the central baseplate spikes of bacteriophages with contractile tails, and genes encoding proteins with PAAR motifs have been frequently found immediately downstream from vgrG-like genes.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 838691163  3 KGFVLLGDKTTHGGKVISASSTMIVNGKKVALIGDMISCPIPfHGPNPIVEGSLEWSSDGKAIVVDGCKCQCGCQVIPS 81
Cdd:cd14744   1 RGIIRLGDKTTHGGVVISGSSTFTIDGRPVARVGDKVTCPKC-KGTGPIVEGGPTFTVDGRPVALDGDRVACGCPLIPS 78

proline-alanine-alanine-arginine (PAAR) domain with uncharacterized C-terminal extension; This domain is found in the PAAR (proline-alanine-alanine-arginine) repeat family of mostly beta- and gamma-proteobacteria, and forms a sharp conical extension on the VgrG spike, a trimeric protein complex of the bacterial type VI secretion system (T6SS). Most members contain C-terminal domain extensions corresponding to several uncharacterized domains such as S-type pyocin, DUF2235, DUF2345 and cytotoxic proteins. However, these terminal domains are exposed to solution, and do not distort the binding site of VgrG. The pointed tip of the PAAR domain is stabilized by a zinc atom positioned close to the cone's vertex and is likely to be important for its integrity during penetration of the target cell envelope. VgrG proteins are orthologous to the central baseplate spikes of bacteriophages with contractile tails, and genes encoding proteins with PAAR motifs have been frequently found immediately downstream from vgrG-like genes.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 838691163  3 KGFVLLGDKTTHGGKVISASSTMIVNGKKVALIGDMISCPIPfHGPNPIVEGSLEWSSDGKAIVVDGCKCQCGCQVIPS 81
Cdd:cd14744   1 RGIIRLGDKTTHGGVVISGSSTFTIDGRPVARVGDKVTCPKC-KGTGPIVEGGPTFTVDGRPVALDGDRVACGCPLIPS 78

proline-alanine-alanine-arginine (PAAR) domain; This domain is found in the PAAR (proline-alanine-alanine-arginine) repeat family, where it forms a sharp conical extension on the VgrG spike, a trimeric protein complex of the bacterial type VI secretion system (T6SS). The T6SS is responsible for translocation of a wide variety of toxic effector molecules, allowing predatory cells to kill prokaryotic as well as eukaryotic prey cells. The pointed tip of the PAAR domain is stabilized by a zinc atom positioned close to the cone's vertex and is likely to be important for its integrity during penetration of the target cell envelope. VgrG proteins are orthologous to the central baseplate spikes of bacteriophages with contractile tails, and genes encoding proteins with PAAR motifs have been frequently found immediately downstream from vgrG-like genes. It has been shown that PAAR proteins are essential for T6SS-mediated secretion and target cell killing by Vibrio cholerae (encodes two PAAR proteins) and Acinetobacter baylyi (encodes three PAAR proteins); inactivation of all these PAAR genes results in inactivation of Hcp secretion as well as T6SS-dependent killing of E. coli.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 838691163  8 LGDKTTHGGKVIS-ASSTMIVNGKKVALIGDMISCPIPFHG----PNPIVEGSLEWSSDGKAIVVDGCKCQCGCQVIPSA 82
Cdd:cd14739   5 VGDPTTHGGTITGpGVPTVLIGGMPAAVVGDMHACVIPPPPahppASPFPPGSATVLIGGRPAARVGDACGCGATIVVGA 84

                ....*.
gi 838691163 83 PDCAIG 88
Cdd:cd14739  85 PTVLIG 90

proline-alanine-alanine-arginine (PAAR) domain; This domain is found in the PAAR (proline-alanine-alanine-arginine) repeat family, where it forms a sharp conical extension on the VgrG spike, a trimeric protein complex of the bacterial type VI secretion system (T6SS). The T6SS is responsible for translocation of a wide variety of toxic effector molecules, allowing predatory cells to kill prokaryotic as well as eukaryotic prey cells. The pointed tip of the PAAR domain is stabilized by a zinc atom positioned close to the cone's vertex and is likely to be important for its integrity during penetration of the target cell envelope. VgrG proteins are orthologous to the central baseplate spikes of bacteriophages with contractile tails, and genes encoding proteins with PAAR motifs have been frequently found immediately downstream from vgrG-like genes. It has been shown that PAAR proteins are essential for T6SS-mediated secretion and target cell killing by Vibrio cholerae (encodes two PAAR proteins) and Acinetobacter baylyi (encodes three PAAR proteins); inactivation of all these PAAR genes results in inactivation of Hcp secretion as well as T6SS-dependent killing of E. coli.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 838691163  6 VLLGDKTT-HGG----KVISASSTMIVNGKKVALIGDMIS---CPIPFHGPNPIVEGSLEWSSDGKAIVVDGCKCQCGCQ 77
Cdd:cd14737   4 ARLGDICTgHGGfpptPVIAGSPDVTVNGKPVLRQGDALAphtCPKHPPHGGVIASGSSTVFINGKPAARVGDPVSCGGT 83

                        90
                ....*....|.
gi 838691163 78 VIPSAPDCAIG 88
Cdd:cd14737  84 VAGGSPNVFIG 94

proline-alanine-alanine-arginine (PAAR) domain with C-terminal extension; This domain is found in the PAAR (proline-alanine-alanine-arginine) repeat family of mostly gamma-proteobacteria, and forms a sharp conical extension on the VgrG spike, a trimeric protein complex of the bacterial type VI secretion system (T6SS). Some members contains C-terminal domain extensions corresponding to Rearrangement hotspot (Rhs) protein repeats and conserved Rhs repeat-associated unique core sequences as well as uncharacterized domains. However, these terminal domains are exposed to solution, and do not distort the binding site of VgrG. Rhs and related YD-peptide repeat proteins are widely distributed in bacteria. Rhs shares similar architecture with distantly related WapA proteins of Bacillus and Listeria species, suggesting intercellular growth inhibition as its primary function. Additionally, a plasmid-encoded Rhs protein has been implicated in bacteriocin production in Pseudomonas savastanoi. The pointed tip of the PAAR domain is stabilized by a zinc atom positioned close to the cone's vertex and is likely to be important for its integrity during penetration of the target cell envelope. VgrG proteins are orthologous to the central baseplate spikes of bacteriophages with contractile tails, and genes encoding proteins with PAAR motifs have been frequently found immediately downstream from vgrG-like genes.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 838691163 14 HGGKVISASSTMIVNGKKVALIGDMISCpipfhgPNPIVEGSLEWSSDGKAIVVDGCKCQCGCQVI 79
Cdd:cd14743  16 HGSTPIGSSSADFFDGLPAARVGDKTSC------GATIVSGSINVLINGKPAAVLGSTTSHGGVVI 75