Phosphomethylpyrimidine synthase

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). This enzyme catalyses the following chemical reaction

5-amino-1-(5-phospho-D-ribosyl)imidazole + S-adenosyl-L-methionine

\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.

References

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.
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.
^ 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.
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.

External links

Phosphomethylpyrimidine+synthase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

External links

Media related to Phosphomethylpyrimidine synthase at Wikimedia Commons

v t e Carbon–carbon lyases (EC 4.1)
4.1.1: Carboxy-lyases	Acetoacetate decarboxylase Adenosylmethionine decarboxylase Arginine decarboxylase Aromatic L-amino acid decarboxylase Glutamate decarboxylase Histidine decarboxylase Lysine decarboxylase Malonyl-CoA decarboxylase Ornithine decarboxylase Oxaloacetate decarboxylase Phosphoenolpyruvate carboxykinase Phosphoenolpyruvate carboxylase Phosphoribosylaminoimidazole carboxylase Pyrophosphomevalonate decarboxylase Pyruvate decarboxylase RuBisCO Uridine monophosphate synthetase/Orotidine 5'-phosphate decarboxylase Uroporphyrinogen III decarboxylase
4.1.2: Aldehyde-lyases	Fructose-bisphosphate aldolase Aldolase A Aldolase B Aldolase C 2-hydroxyphytanoyl-CoA lyase Threonine aldolase
4.1.3: Oxo-acid-lyases	Isocitrate lyase 3-hydroxy-3-methylglutaryl-CoA lyase
4.1.99: Other	Tryptophanase Photolyase CPD lyase Spore photoproduct lyase

v t e Enzymes
Activity	Active site Binding site Catalytic triad Oxyanion hole Enzyme promiscuity Diffusion-limited enzyme Cofactor Enzyme catalysis
Regulation	Allosteric regulation Cooperativity Enzyme inhibitor Enzyme activator
Classification	EC number Enzyme superfamily Enzyme family List of enzymes
Kinetics	Enzyme kinetics Eadie–Hofstee diagram Hanes–Woolf plot Lineweaver–Burk plot Michaelis–Menten kinetics
Types	EC1 Oxidoreductases (list) EC2 Transferases (list) EC3 Hydrolases (list) EC4 Lyases (list) EC5 Isomerases (list) EC6 Ligases (list) EC7 Translocases (list)

Portal:

Biology

Category:

EC 4.1.99