Structural highlights
1g4e is a 2 chain structure with sequence from Bacillus subtilis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
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| Related: | 2tps, 1g4s, 1g4p, 1g4t, 1g6c, 1g67, 1g69 |
| Gene: | THIC (Bacillus subtilis) |
| Activity: | Thiamine-phosphate diphosphorylase, with EC number 2.5.1.3 |
| Resources: | FirstGlance, OCA, RCSB, PDBsum |
Function
[THIE_BACSU] Condenses 4-methyl-5-(beta-hydroxyethyl)thiazole monophosphate (THZ-P) and 2-methyl-4-amino-5-hydroxymethyl pyrimidine pyrophosphate (HMP-PP) to form thiamine monophosphate (TMP). Is also able to use the 2-methoxy analog MeO-HMP-PP, as substrate in vitro, but not the 2-trifluoromethyl analog CF(3)-HMP-PP.[1] [2]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Thiamin phosphate synthase catalyzes the formation of thiamin phosphate from 4-amino-5-(hydroxymethyl)-2-methylpyrimidine pyrophosphate and 5-(hydroxyethyl)-4-methylthiazole phosphate. Several lines of evidence suggest that the reaction proceeds via a dissociative mechanism. The previously determined crystal structure of thiamin phosphate synthase in complex with the reaction products, thiamin phosphate and magnesium pyrophosphate, provided a view of the active site and suggested a number of additional experiments. We report here seven new crystal structures primarily involving crystals of S130A thiamin phosphate synthase soaked in solutions containing substrates or products. We prepared S130A thiamin phosphate synthase with the intent of characterizing the enzyme-substrate complex. Surprisingly, in three thiamin phosphate synthase structures, the active site density cannot be modeled as either substrates or products. For these structures, the best fit to the electron density is provided by a model that consists of independent pyrimidine, pyrophosphate, and thiazole phosphate fragments, consistent with a carbenium ion intermediate. The resulting carbenium ion is likely to be further stabilized by proton transfer from the pyrimidine amino group to the pyrophosphate to give the pyrimidine iminemethide, which we believe is the species that is observed in the crystal structures.
Structural characterization of the enzyme-substrate, enzyme-intermediate, and enzyme-product complexes of thiamin phosphate synthase.,Peapus DH, Chiu HJ, Campobasso N, Reddick JJ, Begley TP, Ealick SE Biochemistry. 2001 Aug 28;40(34):10103-14. PMID:11513589[3]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Zhang Y, Taylor SV, Chiu HJ, Begley TP. Characterization of the Bacillus subtilis thiC operon involved in thiamine biosynthesis. J Bacteriol. 1997 May;179(9):3030-5. PMID:9139923
- ↑ Reddick JJ, Nicewonger R, Begley TP. Mechanistic studies on thiamin phosphate synthase: evidence for a dissociative mechanism. Biochemistry. 2001 Aug 28;40(34):10095-102. PMID:11513588
- ↑ Peapus DH, Chiu HJ, Campobasso N, Reddick JJ, Begley TP, Ealick SE. Structural characterization of the enzyme-substrate, enzyme-intermediate, and enzyme-product complexes of thiamin phosphate synthase. Biochemistry. 2001 Aug 28;40(34):10103-14. PMID:11513589
