Protein Family Models

Early annotation suggested this family, SepSecS, of several eukaryotic and archaeal proteins, was involved in antigen-antibodies responses in the liver and pancreas [1,2]. Structural studies show that the family is O-phosphoseryl-tRNA(Sec) selenium transferase, an enzyme involved in the synthesis of the amino acid selenocysteine (Sec). Sec is the only amino acid whose biosynthesis occurs on its cognate transfer RNA (tRNA). SepSecS catalyses the final step in the formation of the amino acid [3,4,5,6]. The early observation that autoantibodies isolated from patients with type I autoimmune hepatitis targeted a ribonucleoprotein complex containing tRNASec led to the identification and characterisation of the archaeal and the human SepSecS [2]. SepSecS forms its own branch in the family of fold-type I pyridoxal phosphate (PLP) enzymes that goes back to the last universal common ancestor which explains why the archaeal sequences Swiss:Q8TXK0 and Swiss:Q8TYR3 are annotated as being pyridoxal phosphate-dependent enzymes. [1]. 10801173. Identification of target antigen for SLA/LP autoantibodies in autoimmune hepatitis. Wies I, Brunner S, Henninger J, Herkel J, Kanzler S, Meyer zum Buschenfelde KH, Lohse AW;. Lancet 2000;355:1510-1515. [2]. 11481605. A bioinformatical approach suggests the function of the autoimmune hepatitis target antigen soluble liver antigen/liver pancreas. Kernebeck T, Lohse AW, Grotzinger J;. Hepatology 2001;34:230-233. [3]. 17194211. Biosynthesis of selenocysteine on its tRNA in eukaryotes. Xu XM, Carlson BA, Mix H, Zhang Y, Saira K, Glass RS, Berry MJ, Gladyshev VN, Hatfield DL;. PLoS Biol. 2007;5:e4. [4]. . TRUNCATED at 1650 bytes (from Pfam)

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2024-10-16

Date:

2024-08-14

Date:

2024-08-14

This domain is found in amino transferases, and other enzymes including cysteine desulphurase EC:4.4.1.-. (from Pfam)

Date:

2024-08-14

Date:

2024-08-14

The members of this family are probably all pyridoxal-phosphate-dependent aminotransferase enzymes with a variety of molecular functions. The family includes StsA Swiss:P72454, StsC Swiss:P77952 and StsS [1]. The aminotransferase activity was demonstrated for purified StsC protein as the L-glutamine:scyllo-inosose aminotransferase EC:2.6.1.50, which catalyses the first amino transfer in the biosynthesis of the streptidine subunit of streptomycin [1]. [1]. 9238101. Identification of stsC, the gene encoding the L-glutamine:scyllo-inosose aminotransferase from streptomycin-producing Streptomycetes. Ahlert J, Distler J, Mansouri K, Piepersberg W;. Arch Microbiol 1997;168:102-113. (from Pfam)

Date:

2024-10-16

aminotransferase class I/II-fold pyridoxal phosphate-dependent enzyme similar to Bacillus subtilis arginine decarboxylase that catalyzes the formation of agmatine from arginine

Date:

2023-09-19