Hiraga K, Eto T, Yoshioka I, Oda K
Department of Applied Biology, Faculty of Textile Science, Kyoto Institute of Technology, Japan.
Biosci Biotechnol Biochem. 1998 Feb;62(2):347-53. doi: 10.1271/bbb.62.347.
A gene encoding a novel intracellular sorbitol oxidase of a soil bacterium, Streptomyces sp. H-7775, was cloned and sequenced. The gene consists of an open reading frame of 1,260-bp encoding a protein of 420 amino acids with a molecular weight of 45,148. Deduced amino acid sequence of the gene has 25.3% identity and 68.1% similarity to that of rat L-gulonolactone oxidase at the overall amino acids. Nucleotide-binding motifs were not found in the deduced amino acid sequence of SOX protein. We succeeded in expressing recombinant sorbitol oxidase with covalently bound FAD in E. coli at about a 4,000-fold higher total enzyme activity than that of the Streptomyces sp. H-7775. The enzymatic properties of the recombinant SOX were similar to those of the enzyme from Streptomyces sp. H-7775. This is the first report of the cloning and expression of a newly categorized enzyme, sorbitol oxidase, from Streptomyces sp.
编码土壤细菌链霉菌属H-7775新型细胞内山梨醇氧化酶的基因被克隆并测序。该基因由一个1260bp的开放阅读框组成，编码一个420个氨基酸的蛋白质，分子量为45148。该基因推导的氨基酸序列与大鼠L-古洛糖酸内酯氧化酶的整体氨基酸序列具有25.3%的同一性和68.1%的相似性。在SOX蛋白推导的氨基酸序列中未发现核苷酸结合基序。我们成功地在大肠杆菌中表达了与FAD共价结合的重组山梨醇氧化酶，其总酶活性比链霉菌属H-7775高约4000倍。重组SOX的酶学性质与链霉菌属H-7775的酶相似。这是首次报道从链霉菌属克隆和表达新分类的酶——山梨醇氧化酶。
