Bifunctional enzyme fusion of 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase
Bifunctional enzyme fusion of 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase
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DOI：
10.1007/s00253-007-1023-8
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发表时间：
2007-08-01
影响因子：
5
通讯作者：
Sakai, Yasuyoshi
中科院分区：
文献类型：
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作者：
Orita, Izumi;Sakamoto, Naoki;Sakai, Yasuyoshi
3-己醛糖6-磷酸合成酶（HPS）和6-磷酸3-己醛异构酶（PHI）是单磷酸核酮糖（RuMP）途径中催化顺序反应的关键酶。在这项研究中，我们从甲基营养杆菌胃分枝杆菌MB19中获得了hps和phi基因的两个融合基因构建体（即hps-phi和phi-hps）。HPS - PHI基因产物在室温下同时具有HPS和PHI活性，并且比单个酶的简单混合物更有效地催化了序列反应。phip -hps基因产物未表现出任何酶活性。携带hps-phi基因的大肠杆菌菌株在含甲醛培养基中比宿主菌株更有效地消耗甲醛，并表现出更好的生长。我们的研究结果表明，工程融合基因有可能用于在各种生物体中建立抗甲醛解毒系统。
The formaldehyde-fixing enzymes, 3-Hexulose6-phosphate synthase (HPS) and 6-phospho-3-hexuloisomerase (PHI), are the key enzymes catalyzing sequential reactions in the ribulose monophosphate (RuMP) pathway. In this study, we generated two fused gene constructs of the hps and phi genes (i.e.,hps-phi and phi-hps) from a methylotrophic bacterium Mycobacterium gastri MB19. The gene product of hps-phi exhibited both HPS and PHI activities at room temperature and catalyzed the sequential reactions more efficiently than a simple mixture of the individual enzymes. The gene product of phi-hps failed to display any enzyme activity. Escherichia coli strains harboring the hps-phi gene consumed formaldehyde more efficiently and exhibited better growth in a formaldehyde-containing medium than the host strain. Our results demonstrate that the engineered fusion gene has the possibility to be used to establish a formaldehyde-resistance detoxification system in various organisms.