• 主题
高级搜索  >
历史搜索 清空历史
首页> 美国卫生研究院文献>Applied and Environmental Microbiology >A Novel β-N-Acetylglucosaminidase from Streptomyces thermoviolaceus OPC-520: Gene Cloning Expression and Assignment to Family 3 of the Glycosyl Hydrolases
【2h】

A Novel β-N-Acetylglucosaminidase from Streptomyces thermoviolaceus OPC-520: Gene Cloning Expression and Assignment to Family 3 of the Glycosyl Hydrolases

机译：一种来自嗜热链霉菌OPC-520的新型β-N-乙酰氨基葡萄糖苷酶：基因克隆表达和糖基水解酶家族3的分配

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务，本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文，但由于OA文献来源多样且变更频繁，仍可能出现获取不到、文献不完整或与标题不符等情况，如果获取不到我们将提供退款服务。请知悉。
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A β-N-acetylglucosaminidase gene (nagA) of Streptomyces thermoviolaceus OPC-520 was cloned in Streptomyces lividans 66. The nucleotide sequence of the gene, which encodes NagA, revealed an open reading frame of 1,896 bp, encoding a protein with an Mr of 66,329. The deduced primary structure of NagA was confirmed by comparison with the N-terminal amino acid sequence of the cloned β-N-acetylglucosaminidase expressed by S. lividans. The enzyme shares no sequence similarity with the classical β-N-acetylglucosaminidases belonging to family 20. However, NagA, which showed no detectable β-glucosidase activity, revealed homology with microbial β-glucosidases belonging to family 3; in particular, striking homology with the active-site regions of β-glucosidases was observed. Thus, the above-mentioned results indicate that NagA from S. thermoviolaceus OPC-520 is classified as a family 3 glycosyl hydrolase. The enzyme activity was optimal at 60°C and pH 5.0, and the apparent Km and Vmax values for p-nitrophenyl-β-N-acetylglucosamine were 425.7 μM and 24.8 μmol min−1 mg of protein−1, respectively.
机译：紫链霉菌OPC-520的β-N-乙酰氨基葡糖苷酶基因（nagA）被克隆到lividans链霉菌66中。该基因的核苷酸序列编码NagA，揭示了一个1,896 bp的开放阅读框，其编码的Mr为66,329。通过与由S.lividans表达的克隆的β-N-乙酰氨基葡糖苷酶的N-末端氨基酸序列比较，证实了推导的NagA一级结构。该酶与家族20的经典β-N-乙酰氨基葡糖苷酶没有序列相似性。但是，NagA没有显示可检测的β-葡萄糖苷酶活性，与第三族的微生物β-葡萄糖苷酶具有同源性。特别地，观察到与β-葡萄糖苷酶的活性位点区域具有惊人的同源性。因此，上述结果表明，来自嗜热链球菌OPC-520的NagA被归类为3族糖基水解酶。酶的活性在60°C和pH 5.0时最佳，对硝基苯基-β-N-乙酰氨基葡萄糖的表观Km和Vmax值为425.7μM和24.8μmolmin -1 mg蛋白< sup> -1 。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
代理获取

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号