A novel glucose 6-phosphate isomerase from Listeria monocytogenes.
A novel glucose 6-phosphate isomerase from Listeria monocytogenes.
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一种来自单核细胞增生李斯特菌的新型葡萄糖 6-磷酸异构酶。
DOI：
10.1007/s10930-014-9577-7
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Woodard,RonaldW
中科院分区：
文献类型：
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作者：
Cech,DavidL;Wang,Pan-Fen;Holt,MelissaC;Assimon,VictoriaA;Schaub,JeffreyM;Holler,TodP;Woodard,RonaldW
d-阿拉伯糖5-磷酸异构酶（API）催化d-核酮糖5-磷酸和d-阿拉伯糖5-磷酸（A5P）的相互转化。A5P是3-脱氧-d-甘露-辛酮糖酸（Kdo）生物合成的中间体，3-脱氧-d-甘露-辛酮糖酸（Kdo）是脂多糖（在革兰氏阴性菌的外膜中发现的脂多糖）的必需组分。革兰氏阳性菌单核细胞增生李斯特菌（Listeria monocytogenes）基因组中含有一个编码糖异构酶结构域API的基因Q723 E8，该基因与大肠杆菌CFT 073的4种API中唯一缺少胱硫醚-β-合酶结构域的c3406具有显著的相似性。然而，单核细胞增生李斯特菌缺乏编码Kdo生物合成途径的任何其他酶的基因。认识到在革兰氏阳性细菌中发现API可以提供对A5 P在细胞中的替代生理作用的了解，我们制备并纯化了重组Q723 E8。我们发现Q723 E8不具有API活性，而是一种新的GPI（d-葡萄糖6-磷酸异构酶）。然而，Q723E8的GPI活性与先前描述的GPI相比较弱。单核细胞增生李斯特菌含有已被充分研究的双结构域细菌GPI的直系同源物，因此这可能是多余的。基于这一证据，葡萄糖利用可能不是Q723E8的主要生理作用。
d-Arabinose 5-phosphate isomerases (APIs) catalyze the interconversion ofd-ribulose 5-phosphate andd-arabinose 5-phosphate (A5P). A5P is an intermediate in the biosynthesis of 3-deoxy-d-manno-octulosonate (Kdo), an essential component of lipopolysaccharide, the lipopolysaccharide found in the outer membrane of Gram-negative bacteria. The genome of the Gram-positive pathogenListeria monocytogenescontains a gene encoding a putative sugar isomerase domain API, Q723E8, with significant similarity to c3406, the only one of four APIs fromEscherichia coliCFT073 that lacks a cystathionine-β-synthase domain. However,L.monocytogeneslacks genes encoding any of the other enzymes of the Kdo biosynthesis pathway. Realizing that the discovery of an API in a Gram-positive bacterium could provide insight into an alternate physiological role of A5P in the cell, we prepared and purified recombinant Q723E8. We found that Q723E8 does not possess API activity, but instead is a novel GPI (d-glucose 6-phosphate isomerase). However, the GPI activity of Q723E8 is weak compared with previously described GPIs.L.monocytogenescontains an ortholog of the well-studied two-domain bacterial GPI, so this maybe redundant. Based on this evidence glucose utilization is likely not the primary physiological role of Q723E8.