{"metadata":{"accession":"PS00801","entry_id":null,"type":"conserved_site","go_terms":null,"source_database":"prosite","member_databases":null,"integrated":"IPR049557","hierarchy":null,"name":{"name":"Transketolase signature 1","short":"TRANSKETOLASE_1"},"description":[{"text":"<p>Transketolase (EC 2.2.1.1) (TK) catalyzes the reversible transfer of a\ntwo-carbon ketol unit from xylulose 5-phosphate to an aldose receptor, such as\nribose 5-phosphate, to form sedoheptulose 7-phosphate and glyceraldehyde 3-\nphosphate. This enzyme, together with transaldolase, provides a link between\nthe glycolytic and pentose-phosphate pathways.\n\nTK requires thiamine pyrophosphate as a cofactor. In most sources where TK has\nbeen purified, it is a homodimer of approximately 70 Kd subunits. TK sequences\nfrom a variety of eukaryotic and prokaryotic sources [[cite:PUB00000209]][[cite:PUB00000362]] show that the\nenzyme has been evolutionarily conserved.\n\nIn the peroxisomes of methylotrophic yeast Hansenula polymorpha, there is a\nhighly related enzyme, dihydroxy-acetone synthase (DHAS) (EC 2.2.1.3) (also\nknown as formaldehyde transketolase), which exhibits a very unusual\nspecificity by including formaldehyde amongst its substrates.\n\n1-deoxyxylulose-5-phosphate synthase (DXP synthase) [[cite:PUB00004906]] is an enzyme so far\nfound in bacteria (gene dxs) and plants (gene CLA1) which catalyzes the\nthiamine pyrophosphoate-dependent acyloin condensation reaction between carbon\natoms 2 and 3 of pyruvate and glyceraldehyde 3-phosphate to yield 1-deoxy-D-\nxylulose-5-phosphate (dxp), a precursor in the biosynthetic pathway to\nisoprenoids, thiamine (vitamin B1), and pyridoxol (vitamin B6). DXP synthase\nis evolutionary related to TK.\n\nWe selected two regions of TK as signature patterns. The first, located in the\nN-terminal section, contains a histidine residue which appears to function in\nproton transfer during catalysis [[cite:PUB00001222]]. The second, located in the central\nsection, contains conserved acidic residues that are part of the active cleft\nand may participate in substrate-binding [[cite:PUB00001222]].</p>","llm":false,"checked":false,"updated":false}],"wikipedia":null,"literature":{"PUB00001222":{"PMID":1628611,"ISBN":null,"volume":"11","issue":"7","year":1992,"title":"Three-dimensional structure of transketolase, a thiamine diphosphate dependent enzyme, at 2.5 A resolution.","URL":null,"raw_pages":"2373-9","medline_journal":"EMBO J","ISO_journal":"EMBO J.","authors":["Lindqvist Y","Schneider G","Ermler U","Sundstrom M."],"DOI_URL":"http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=EBI&pubmedid=1628611"},"PUB00000362":{"PMID":1737042,"ISBN":null,"volume":"31","issue":"6","year":1992,"title":"DNA sequence of the yeast transketolase gene.","URL":null,"raw_pages":"1892-6","medline_journal":"Biochemistry","ISO_journal":"Biochemistry","authors":["Fletcher TS","Kwee IL","Nakada T","Largman C","Martin BM."],"DOI_URL":"http://dx.doi.org/10.1021/bi00121a044"},"PUB00004906":{"PMID":9371765,"ISBN":null,"volume":"94","issue":"24","year":1997,"title":"Identification of a thiamin-dependent synthase in Escherichia coli required for the formation of the 1-deoxy-D-xylulose 5-phosphate precursor to isoprenoids, thiamin, and pyridoxol.","URL":null,"raw_pages":"12857-62","medline_journal":"Proc Natl Acad Sci U S A","ISO_journal":"Proc. Natl. Acad. Sci. U.S.A.","authors":["Sprenger GA","Schorken U","Wiegert T","Grolle S","de Graaf AA","Taylor SV","Begley TP","Bringer-Meyer S","Sahm H."],"DOI_URL":"http://dx.doi.org/10.1073/pnas.94.24.12857"},"PUB00000209":{"PMID":1567394,"ISBN":null,"volume":"183","issue":"3","year":1992,"title":"Nucleotide and predicted amino acid sequence of a cDNA clone encoding part of human transketolase.","URL":null,"raw_pages":"1159-66","medline_journal":"Biochem Biophys Res Commun","ISO_journal":"Biochem. Biophys. Res. Commun.","authors":["Abedinia M","Layfield R","Jones SM","Nixon PF","Mattick JS."],"DOI_URL":"http://dx.doi.org/10.1016/S0006-291X(05)80312-2"}},"set_info":null,"overlaps_with":null,"counters":{"subfamilies":0,"domain_architectures":0,"interactions":0,"matches":51760,"pathways":0,"proteins":51751,"proteomes":17834,"sets":0,"structural_models":{"alphafold":40278,"bfvd":0},"structures":93,"taxa":32473},"entry_annotations":{},"cross_references":{},"is_llm":false,"is_reviewed_llm":false,"is_updated_llm":false,"representative_structure":null}}