A new thiamin salvage pathway
A new thiamin salvage pathway
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DOI：
10.1038/nchembio.2007.13
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发表时间：
2007-08-01
影响因子：
14.8
通讯作者：
Begley, Tadhg P.
中科院分区：
文献类型：
--
作者：
Jenkins, Amy Haas;Schyns, Ghislain;Begley, Tadhg P.
硫胺素降解酶硫胺素II的生理功能，已经逃避了研究人员超过50年。在这里，我们证明，这种酶参与再生的硫胺素嘧啶，而不是在硫胺素降解，我们确定了一个新的途径参与打捞碱降解形式的硫胺素。该途径广泛分布于细菌、古细菌和真核生物中。在该途径中，硫胺素水解产物如N-甲酰基-4-氨基-5-氨基甲基-2-甲基嘧啶（甲酰氨基嘧啶; 15）使用ThiXYZ转运系统转运到细胞中，通过ylmB编码的酰胺水解酶脱甲酰化并水解为4-氨基-5-羟甲基-2-甲基嘧啶（HMP; 6）--一种从头硫胺素生物合成途径的中间体。据我们所知，这是硫胺素补救途径的第一个例子，涉及硫胺素类似物产生的降解的一个杂环的辅因子。
The physiological function for thiaminase II, a thiamin-degrading enzyme, has eluded investigators for more than 50 years. Here, we demonstrate that this enzyme is involved in the regeneration of the thiamin pyrimidine rather than in thiamin degradation, and we identify a new pathway involved in the salvage of base-degraded forms of thiamin. This pathway is widely distributed among bacteria, archaea and eukaryotes. In this pathway, thiamin hydrolysis products such as N-formyl-4-amino-5-aminomethyl-2-methylpyrimidine (formylaminopyrimidine; 15) are transported into the cell using the ThiXYZ transport system, deformylated by the ylmB-encoded amidohydrolase and hydrolyzed to 4-amino-5-hydroxymethyl-2methylpyrimidine (HMP; 6) - an intermediate on the de novo thiamin biosynthetic pathway. To our knowledge this is the first example of a thiamin salvage pathway involving thiamin analogs generated by degradation of one of the heterocyclic rings of the cofactor.