Phosphomethylpyrimidine synthase (original) (raw)

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Phosphomethylpyrimidine synthase
Phosphomethylpyrimidine synthase dimer, Arabidopsis thaliana
Identifiers
EC no. 4.1.99.17
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
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Phosphomethylpyrimidine synthase (EC 4.1.99.17, thiC (gene)) is an enzyme with systematic name 5-amino-1-(5-phospho-D-ribosyl)imidazole formate-lyase (decarboxylating, 4-amino-2-methyl-5-phosphomethylpyrimidine-forming).[1][2][3] This enzyme catalyses the following chemical reaction

5-amino-1-(5-phospho-D-ribosyl)imidazole + _S_-adenosyl-L-methionine ⇌ {\displaystyle \rightleftharpoons } {\displaystyle \rightleftharpoons } 4-amino-2-methyl-5-phosphomethylpyrimidine + 5′-deoxyadenosine + L-methionine + formate + CO

This enzyme binds a 4Fe-4S cluster.

The starting material is 5-aminoimidazole ribotide, which undergoes a rearrangement reaction via radical intermediates which incorporate the blue, green and red fragments shown into the product.[3][4]

  1. ^ Chatterjee A, Li Y, Zhang Y, Grove TL, Lee M, Krebs C, Booker SJ, Begley TP, Ealick SE (December 2008). "Reconstitution of ThiC in thiamine pyrimidine biosynthesis expands the radical SAM superfamily". Nature Chemical Biology. 4 (12): 758–65. doi:10.1038/nchembio.121. PMC 2587053. PMID 18953358.
  2. ^ Martinez-Gomez NC, Poyner RR, Mansoorabadi SO, Reed GH, Downs DM (January 2009). "Reaction of AdoMet with ThiC generates a backbone free radical". Biochemistry. 48 (2): 217–9. doi:10.1021/bi802154j. PMC 2654281. PMID 19113839.
  3. ^ a b Chatterjee A, Hazra AB, Abdelwahed S, Hilmey DG, Begley TP (November 2010). "A "radical dance" in thiamin biosynthesis: mechanistic analysis of the bacterial hydroxymethylpyrimidine phosphate synthase". Angewandte Chemie. 49 (46): 8653–6. doi:10.1002/anie.201003419. PMC 3147014. PMID 20886485.
  4. ^ Begley, Tadhg P. (2006). "Cofactor biosynthesis: An organic chemist's treasure trove". Natural Product Reports. 23 (1): 15–18. doi:10.1039/b207131m. PMID 16453030.