MetaCyc Enzyme: thiazole synthase

Gene: thiG Accession Number: BSU11690 (MetaCyc)

Synonyms: yjbT

Species: Bacillus subtilis subtilis 168

Thiazole synthase (ThiG) catalyzes a very complex reaction that produces the thiazole moiety of thiamin diphosphate. The enzyme requires three inputs - 1-deoxy-D-xylulose 5-phosphate (DXP), 2-iminoacetate, and a carboxy-adenylated-[ThiS sulfur-carrier protein] [Park03].

Based on current understanding, the reaction starts when DXP binds to lysine 96 of the thiazole synthase, forming an imine that tautomerizes to aminoketone [Dorrestein04]. Addition of the ThiS-thiocarboxylate, (formed separately by reactions catalyzed by ThiF and IscS) is followed by an S/O acyl shift and loss of water, where the ThiS-thiocarboxylate sulfur is exchanged with an oxygen from DXP [Dorrestein04a]. In the next step the ThiS protein leaves the complex and 2-iminoacetate (formed by ThiO from glycine) is added. At this point a cyclization occurs via a transimination that involves the release of ThiG, producing the final product of the enzyme, 2-[(2R,5Z)-(2-carboxy-4-methylthiazol-5(2H)-ylidene]ethyl phosphate [Hazra09].

Locations: cytosol

Map Position: [1,245,041 -> 1,245,811]

Molecular Weight of Polypeptide: 27.022 kD (from nucleotide sequence)

Unification Links: DBTBS Operons:thiG , Entrez:2633523 , GenoList (SubtiList):BSU11690 , GOA:O31618 , Mint:MINT-8365876 , Protein Model Portal:O31618 , SMR:O31618 , String:224308.BSU11690 , String:BSU11690 , SubtilisWiki:thiG , SubtiWiki:thiG , UniProt:O31618

Relationship Links: InterPro:IN-FAMILY:IPR008867 , InterPro:IN-FAMILY:IPR013785 , PDB:Structure:1TYG , PDB:Structure:1XM3 , Pfam:IN-FAMILY:PF05690

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0008152 - metabolic process Inferred by computational analysis [GOA01a]
GO:0009228 - thiamine biosynthetic process Inferred by computational analysis [GOA00, GOA01a]
Molecular Function: GO:0003824 - catalytic activity Inferred by computational analysis [GOA01a]
GO:0016829 - lyase activity Inferred by computational analysis [GOA00]
Cellular Component: GO:0005737 - cytoplasm Inferred by computational analysis [GOA07, GOA00]


Imported from BsubCyc 20-Sep-2011 by Caspi R , SRI International
Revised 20-Sep-2011 by Caspi R , SRI International

Enzymatic reaction of: thiazole synthase

EC Number:

1-deoxy-D-xylulose 5-phosphate + 2-iminoacetate + a thiocarboxy-[ThiS-Protein] <=> 2-[(2R,5Z)-(2-carboxy-4-methylthiazol-5(2H)-ylidene]ethyl phosphate + a ThiS sulfur-carrier protein + 2 H2O

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

The reaction is favored in the direction shown.

In Pathways: superpathway of thiamin diphosphate biosynthesis II , thiazole biosynthesis II (Bacillus)


Dorrestein04: Dorrestein PC, Zhai H, Taylor SV, McLafferty FW, Begley TP (2004). "The biosynthesis of the thiazole phosphate moiety of thiamin (vitamin B1): the early steps catalyzed by thiazole synthase." J Am Chem Soc 126(10);3091-6. PMID: 15012138

Dorrestein04a: Dorrestein PC, Zhai H, McLafferty FW, Begley TP (2004). "The biosynthesis of the thiazole phosphate moiety of thiamin: the sulfur transfer mediated by the sulfur carrier protein ThiS." Chem Biol 11(10);1373-81. PMID: 15489164

GOA00: GOA (2000). "Gene Ontology annotation based on Swiss-Prot keyword mapping."

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA07: GOA, UniProt (2007). "Gene Ontology annotation based on Swiss-Prot Subcellular Location vocabulary mapping."

Hazra09: Hazra A, Chatterjee A, Begley TP (2009). "Biosynthesis of the thiamin thiazole in Bacillus subtilis: identification of the product of the thiazole synthase-catalyzed reaction." J Am Chem Soc 131(9);3225-9. PMID: 19216519

Park03: Park JH, Dorrestein PC, Zhai H, Kinsland C, McLafferty FW, Begley TP (2003). "Biosynthesis of the thiazole moiety of thiamin pyrophosphate (vitamin B1)." Biochemistry 42(42);12430-8. PMID: 14567704

Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 19.0 on Mon Oct 5, 2015, BIOCYC14B.