ubiquitin-like (Ubl) domain found in a group of small sulfide carrier proteins; Ubiquitin-like (Ubl) domain found in a group of small sulfide carrier proteins This family includes ThiS, MoaD, CysO, QbsE, and their homologs, which are structurally homologous to ubiquitin (Ub) and may function as the sulfide donor for the biosynthesis of thiamin, molybdopterin, cysteine, thioquinolobactin, and other sulfur-containing natural products. Ub is a protein modifier in eukaryotes that is involved in various cellular processes, including transcriptional regulation, cell cycle control, and DNA repair. Ubiquitination is comprised of a cascade of E1, E2 and E3 enzymes that results in a covalent bond between the C-terminus of Ub and the epsilon-amino group of a substrate lysine. Like Ub, small sulfide carrier proteins in this family are adenylated at a diglycyl C-terminus by specific activating proteins. The adenylated C-terminus is subsequently converted to a thiocarboxylate, serving as the sulfide source. Those activating proteins are diverse and show little sequence similarity. This family also includes the small archaeal modifier protein (SAMP), including SAMP1, SAMP2 and SAMP3, which are Ub-like proteins that function as protein modifiers and are required for the production of sulfur-containing biomolecules in the archaeon Haloferax volcanii. SAMP1 and SAMP2 are involved in sulfur transfer during molybdenum cofactor biosynthesis and tRNA thiolation much like MoaD and Urm1, respectively. They can form covalent conjugates with their protein targets through an isopeptide linkage via their C-terminal diglycine motif in a streamlined archaeal E1-dependent pathway. SAMP2 also forms homo-conjugates through the intermolecular isopeptide bond between the C-terminal Gly and the Lys58 side chain, a feature that likely resembles polyubiquitination. SAMP3 conjugates are dependent on the Ub-activating E1 enzyme homolog of archaea (UbaA) for synthesis and are cleaved by the JAMM/MPN+ domain metalloprotease HvJAMM1.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2535606270  3 VTLRFFARFGELLGKSRVVDAPENTSLSDLIrDAASQNSEGYGSIFDEHGAFRDFVILMRNGKRVPAAAaDRTLLSEGDE 82
Cdd:cd17040    1 VKVRLFGALREAGAGEEEIEVEGGTTVRDLL-DALSERYPGLFEALDEDGELRPFILVFVNGRDVRLDD-GLTPLKDGDE 78

                         90
                 ....*....|
gi 2535606270 83 VAVFPPVAGG 92
Cdd:cd17040   79 VDILPPVAGG 88

ThiS family; ThiS (thiaminS) is a 66 aa protein involved in sulphur transfer. ThiS is coded in the thiCEFSGH operon in E. coli. This family of proteins have two conserved Glycines at the COOH terminus. Thiocarboxylate is formed at the last G in the activation process. Sulphur is transferred from ThiI to ThiS in a reaction catalyzed by IscS. MoaD, a protein involved sulphur transfer in molybdopterin synthesis, is about the same length and shows limited sequence similarity to ThiS. Both have the conserved GG at the COOH end.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2535606270  5 LRFFARFGELLGKSRVVdaPENTSLSDLIRDAASQnsegygsifdeHGAFRDFVILMRNGKRVPAAAADrTLLSEGDEVA 84
Cdd:pfam02597  1 VLLNAELRELAGKDEEL--AEGATVAELLEALGLR-----------YPELRERVAVAVNGEIVPRLWLD-TPLKDGDEVA 66

                 ....*...
gi 2535606270 85 VFPPVAGG 92
Cdd:pfam02597 67 IIPPVGGG 74

ubiquitin-like (Ubl) domain found in a group of small sulfide carrier proteins; Ubiquitin-like (Ubl) domain found in a group of small sulfide carrier proteins This family includes ThiS, MoaD, CysO, QbsE, and their homologs, which are structurally homologous to ubiquitin (Ub) and may function as the sulfide donor for the biosynthesis of thiamin, molybdopterin, cysteine, thioquinolobactin, and other sulfur-containing natural products. Ub is a protein modifier in eukaryotes that is involved in various cellular processes, including transcriptional regulation, cell cycle control, and DNA repair. Ubiquitination is comprised of a cascade of E1, E2 and E3 enzymes that results in a covalent bond between the C-terminus of Ub and the epsilon-amino group of a substrate lysine. Like Ub, small sulfide carrier proteins in this family are adenylated at a diglycyl C-terminus by specific activating proteins. The adenylated C-terminus is subsequently converted to a thiocarboxylate, serving as the sulfide source. Those activating proteins are diverse and show little sequence similarity. This family also includes the small archaeal modifier protein (SAMP), including SAMP1, SAMP2 and SAMP3, which are Ub-like proteins that function as protein modifiers and are required for the production of sulfur-containing biomolecules in the archaeon Haloferax volcanii. SAMP1 and SAMP2 are involved in sulfur transfer during molybdenum cofactor biosynthesis and tRNA thiolation much like MoaD and Urm1, respectively. They can form covalent conjugates with their protein targets through an isopeptide linkage via their C-terminal diglycine motif in a streamlined archaeal E1-dependent pathway. SAMP2 also forms homo-conjugates through the intermolecular isopeptide bond between the C-terminal Gly and the Lys58 side chain, a feature that likely resembles polyubiquitination. SAMP3 conjugates are dependent on the Ub-activating E1 enzyme homolog of archaea (UbaA) for synthesis and are cleaved by the JAMM/MPN+ domain metalloprotease HvJAMM1.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2535606270  3 VTLRFFARFGELLGKSRVVDAPENTSLSDLIrDAASQNSEGYGSIFDEHGAFRDFVILMRNGKRVPAAAaDRTLLSEGDE 82
Cdd:cd17040    1 VKVRLFGALREAGAGEEEIEVEGGTTVRDLL-DALSERYPGLFEALDEDGELRPFILVFVNGRDVRLDD-GLTPLKDGDE 78

                         90
                 ....*....|
gi 2535606270 83 VAVFPPVAGG 92
Cdd:cd17040   79 VDILPPVAGG 88

ThiS family; ThiS (thiaminS) is a 66 aa protein involved in sulphur transfer. ThiS is coded in the thiCEFSGH operon in E. coli. This family of proteins have two conserved Glycines at the COOH terminus. Thiocarboxylate is formed at the last G in the activation process. Sulphur is transferred from ThiI to ThiS in a reaction catalyzed by IscS. MoaD, a protein involved sulphur transfer in molybdopterin synthesis, is about the same length and shows limited sequence similarity to ThiS. Both have the conserved GG at the COOH end.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2535606270  5 LRFFARFGELLGKSRVVdaPENTSLSDLIRDAASQnsegygsifdeHGAFRDFVILMRNGKRVPAAAADrTLLSEGDEVA 84
Cdd:pfam02597  1 VLLNAELRELAGKDEEL--AEGATVAELLEALGLR-----------YPELRERVAVAVNGEIVPRLWLD-TPLKDGDEVA 66

                 ....*...
gi 2535606270 85 VFPPVAGG 92
Cdd:pfam02597 67 IIPPVGGG 74

ubiquitin-like (Ubl) domain found in small archaeal modifier protein 1 (SAMP1); Ubiquitin-like small archaeal modifier protein 1 (SAMP1) shows a beta-grasp fold of Ub, suggesting that this archaeal Ubl molecule is more closely related to eukaryotic Ub and Ubls than to its prokaryotic counterpart. Several Ub-like structural features such as an N-terminal single lysine residue and di-glycine motif at the C-terminus, spatially isolated, implicate formation of a poly-SAMPylated chainpoly-SAMPylation. SAMP1 can form covalent conjugates with its protein targets through an isopeptide linkage via their C-terminal diglycine motif in a streamlined archaeal E1-dependent pathway. It is involved in sulfur transfer during molybdenum cofactor biosynthesis much like MoaD. This family also includes proteins such as Thermoplasma acidophilum TA0895 and others, all closely related to proteins MoaD.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2535606270  3 VTLRFFARFGELLGKSRV-VDAPEnTSLSDLIRDAASQNSEGYGSIFDEHGAFRDFVILMRNGKRVPAAAADRTLLSEGD 81
Cdd:cd17505    1 VEVKLYATLREVAGSKEVeLDVDG-ATVGEVLDSLVALYPALEGRLITEDGELAEHVIVLVNGRNIRHLEGLETPLKDGD 79

                         90
                 ....*....|.
gi 2535606270 82 EVAVFPPVAGG 92
Cdd:cd17505   80 TIDLFPPVAGG 90

Sulfur carrier protein ThiS (thiamine biosynthesis) [Coenzyme transport and metabolism]; Sulfur carrier protein ThiS (thiamine biosynthesis) is part of the Pathway/BioSystem: Thiamine biosynthesis

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2535606270 16 GKSRVVdaPENTSLSDLIrdaasqnsegygsifDEHGAFRDFVILMRNGKRVPAAAADRTLLSEGDEVAVFPPVAGG 92
Cdd:COG2104    7 GEPREV--PEGTTLADLL---------------EELGLDPKGVAVAVNGEIVPRSQWASTVLKEGDRVEIVTAVGGG 66

thiamine biosynthesis protein ThiS; This model represents ThiS, a small, ubiquitin-like thiamine biosynthesis protein related to MoaD, a molybdenum cofactor biosynthesis protein. Both proteins are involved in sulfur transfer. ThiS has a conserved Gly-Gly C-terminus that is modified, in reactions requiring ThiI, ThiF, IscS, and a sulfur atom from Cys, into the thiocarboxylate that provides the sulfur for thiazole biosynthesis. [Biosynthesis of cofactors, prosthetic groups, and carriers, Thiamine]

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2535606270 16 GKSRVVDAPenTSLSDLIrdaasqnsegygsifDEHGAFRDFVILMRNGKRVPAAAADRTLLSEGDEVAVFPPVAGG 92
Cdd:TIGR01683  5 GEPVEVEDG--TTLAALL---------------ESLGLDPRRVAVAVNGEIVPRSEWDDTILKEGDRIEIVTFVGGG 64

molybdopterin synthase small subunit; Provisional

                         10
                 ....*....|....*.
gi 2535606270 77 LSEGDEVAVFPPVAGG 92
Cdd:PRK11130  66 LTDGDEVAFFPPVTGG 81