Identification of a Xylitol Dehydrogenase Gene from Kluyveromyces marxianus NBRC1777
Identification of a Xylitol Dehydrogenase Gene from Kluyveromyces marxianus NBRC1777
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马克斯克鲁维酵母 NBRC1777 木糖醇脱氢酶基因的鉴定
DOI：
10.1007/s12033-012-9508-9
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发表时间：
2013-02-01
影响因子：
2.6
通讯作者：
Hong Jiong
中科院分区：
文献类型：
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作者：
Li Lulu;Zhang Ling;Hong Jiong
木糖醇脱氢酶（XDH）（EC 1.1.1.9）是酵母和真菌木糖发酵途径中的关键酶之一。从马克斯克鲁维酵母（KluyveromycesmarxianusNBRC 1777）中克隆了编码木糖醇脱氢酶（XDH）的基因XYL 2，并通过破坏和互补分析验证了其体内功能。KmXDH在55 ℃、pH9.5时酶活最高。k（cat）/K（m）的值表明KmXDH更喜欢NAD（+）而不是NADP（+）（k（cat）/K（m NAD）（+）3681/min mM和k（cat）/K（m NADP）（+）1361/min mM）。KmXR和KmXDH之间不同的辅酶偏好性导致了木糖利用途径中NADH的积累。氧化还原失衡可能是导致K在限氧条件下木糖发酵不良的原因之一。marxianus NBRC1777.
Xylitol dehydrogenase (XDH) (EC 1.1.1.9) is one of the key enzymes in the xylose fermentation pathway in yeast and fungi. A xylitol dehydrogenase gene (XYL2) encoding a XDH was cloned from Kluyveromyces marxianus NBRC 1777, and the in vivo function was validated by disruption and complementation analysis. The highest activity of KmXDH could be observed at pH 9.5 during 55A degrees C. The values of k (cat)/K (m) indicate that KmXDH prefers NAD(+) to NADP(+) (k (cat)/K (m NAD) (+) 3681/min mM and k (cat)/K (m NADP) (+) 1361/min mM). The different coenzyme preference between KmXR and KmXDH caused an accumulation of NADH in the xylose utilization pathway. The redox imbalance may be one of the reasons to cause the poor xylose fermentation under oxygen-limited conditions in K. marxianus NBRC1777.