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Function
Thiaminase (Thi) or thiamine pyridinylase cleaves vitamin B1. Thiaminase I catalyzes the elimination of the thiazole ring moiety from the thiamin through substitution of the methylene group with a nitrogenous base or sulfhydryl compound[1]. Thiaminase II catalyzes the hydrolysis of thiamin [2].
Structural highlights
The active site of thiaminase II contains a pyrimidine derivative. Three residues participate in the substrate binding and the pyrimidine ring is sandwiched between two tyrosine residues[3].
- ↑ Kreinbring CA, Remillard SP, Hubbard P, Brodkin HR, Leeper FJ, Hawksley D, Lai EY, Fulton C, Petsko GA, Ringe D. Structure of a eukaryotic thiaminase I. Proc Natl Acad Sci U S A. 2014 Jan 7;111(1):137-42. doi: 10.1073/pnas.1315882110., Epub 2013 Dec 18. PMID:24351929 doi:https://dx.doi.org/10.1073/pnas.1315882110
- ↑ Onozuka M, Konno H, Kawasaki Y, Akaji K, Nosaka K. Involvement of thiaminase II encoded by the THI20 gene in thiamin salvage of Saccharomyces cerevisiae. FEMS Yeast Res. 2008 Mar;8(2):266-75. Epub 2007 Nov 19. PMID:18028398 doi:https://dx.doi.org/10.1111/j.1567-1364.2007.00333.x
- ↑ Toms AV, Haas AL, Park JH, Begley TP, Ealick SE. Structural characterization of the regulatory proteins TenA and TenI from Bacillus subtilis and identification of TenA as a thiaminase II. Biochemistry. 2005 Feb 22;44(7):2319-29. PMID:15709744 doi:https://dx.doi.org/10.1021/bi0478648
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3D Structures of thiaminase
Updated on 25-November-2020
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- Thiaminase I
- 4hcw – amThia I – amoeba
- 4hcy – amThia I + deazathiamin
- 2thi, 3thi – BtThia I – Bacillus thiaminolyticus
- 4thi – BtThia I + pyrimidine derivative
- 4kys – Thia I (mutant) + thiamin – Clostridium botulinum
- Thiaminase II
- 4fn6 – Thia II – Staphylococcus aureus
- 3no6 – Thia II – Staphylococcus epidermidis
- 1yaf – BsThia II – Bacillus subtilis
- 1yak – BsThia II + pyrimidine derivative
- 2qcx – BsThia II (mutant) + pyrimidine derivative
References
