Characterization and gene cloning of L-xylulose reductase involved in L-arabinose catabolism from the pentose-fermenting fungus Rhizomucor pusillus
Characterization and gene cloning of L-xylulose reductase involved in L-arabinose catabolism from the pentose-fermenting fungus Rhizomucor pusillus
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戊糖发酵真菌微小根毛霉 L-木酮糖还原酶参与 L-阿拉伯糖分解代谢的表征和基因克隆
DOI：
10.1080/09168451.2017.1320518
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Yamasaki-Yashiki;S.;Komeda;H.;Hoshino;K.;& Asano;Y.
木酮糖还原酶（LXR）是真菌-阿拉伯糖分解代谢途径中木酮糖还原为木糖醇的催化酶。LXR（RpLXR）是从发酵戊糖的真菌Rhizomucor pusillusNBRC 4578中纯化得到的。天然RpLXR是由29 kDa亚基和优选的NADPH作为辅酶组成的同源四聚体。对木酮糖的Km值为8.71mM，对二羟基丙酮的Km值为3.89mM。编码RpLXR的elxr 3（Rplxr 3）基因全长792 bp，编码263个氨基酸（Mr= 28，341）。RpLXR的氨基酸序列与3-氧代酰基（酰基载体蛋白）还原酶的氨基酸序列高度相似。Rplxr 3基因在大肠杆菌中得到表达，重组RpLXR具有与天然RpLXR相似的性质。Rplxr 3基因在R. pusillusNBRC 4578在β-阿拉伯糖存在下被诱导，而在葡萄糖、木糖和甘露醇存在下被抑制，表明RpLXR参与β-阿拉伯糖的分解代谢途径。
l-Xylulose reductase (LXR) catalyzes the reduction ofl-xylulose to xylitol in the fungall-arabinose catabolic pathway. LXR (RpLXR) was purified from the pentose-fermenting zygomycetous fungusRhizomucor pusillusNBRC 4578. The nativeRpLXR is a homotetramer composed of 29 kDa subunits and preferred NADPH as a coenzyme. TheKmvalues were 8.71 mM forl-xylulose and 3.89 mM for dihydroxyacetone. Thelxr3(Rplxr3) gene encodingRpLXR consists of 792 bp and encodes a putative 263 amino acid protein (Mr= 28,341). The amino acid sequence ofRpLXR showed high similarity to 3-oxoacyl-(acyl-carrier-protein) reductase. TheRplxr3gene was expressed inEscherichia coliand the recombinantRpLXR exhibited properties similar to those of nativeRpLXR. Transcription of theRplxr3gene inR. pusillusNBRC 4578 was induced in the presence ofl-arabinose and inhibited in the presence ofd-glucose,d-xylose, andd-mannitol, indicating thatRpLXR is involved in thel-arabinose catabolic pathway.