Cloning and characterization of a pyridoxine 5′‐phosphate oxidase from silkworm, Bombyx mori
Cloning and characterization of a pyridoxine 5′‐phosphate oxidase from silkworm, Bombyx mori
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DOI：
10.1111/j.1365-2583.2009.00880.x
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发表时间：
2009-06
影响因子：
2.6
通讯作者：
S.-H. Huang;R‐J. Shi;J.Y. Zhang;Z. Wang;L.Q. Huang
中科院分区：
文献类型：
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作者：
S.-H. Huang;R‐J. Shi;J.Y. Zhang;Z. Wang;L.Q. Huang
克隆了家蚕吡哆醇5′-磷酸氧化酶（PNPO）的cDNA序列，并对其进行了结构鉴定（GenBank登录号：DQ 452398）。该cDNA编码257个氨基酸残基的多肽。从大肠杆菌中纯化的重组酶在pH 9.0时表现出最大活性，并测定了5′-磷酸吡哆醇和5′-磷酸吡哆胺底物的Km值为0.65和1.15 µmol/l。发现B.家蚕PNPO与人PNPO的同源性为51.44%，但在B中有几个功能相关的关键氨基酸残基。家蚕PNPO与人和E.大肠杆菌基因。B。家蚕具有PNPO基因的单拷贝，其跨越3.5kb的区域并且包含5个外显子和4个内含子。B。Mori PNPO是同源二聚体，每个单体含有9个反平行β链和5个α螺旋片段。通过计算研究推导出二级结构。
A cDNA encoding Pyridoxine 5′‐phosphate oxidase (PNPO) from Bombyx mori was cloned and characterized (GenBank accession number: DQ452398). The cDNA encodes a polypeptide of 257 amino acid residues. The recombinant enzyme purified from Escherichia coli exhibited maximal activity at pH 9.0, and the Km values for the substrates of pyridoxine 5′‐phosphate and pyridoxamine 5′‐phosphate were determined as 0.65 and 1.15 µmol/l. It was found that B. mori PNPO shares 51.44% homology with humans, but several function‐related, key amino acid residues in B. mori PNPO are different from the human and E. Coli gene. B. mori has a single copy of the PNPO gene, which spans a 3.5 kb region and contains five exons and four introns. B. mori PNPO is a homodimer, with each monomer containing nine antiparallel β‐strands and five α‐helical segments. The secondary structure was deduced from computational study.