...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of bacteriology >Role of α-Methylacyl Coenzyme A Racemase in the Degradation of Methyl-Branched Alkanes by Mycobacterium sp. Strain P101
【24h】

Role of α-Methylacyl Coenzyme A Racemase in the Degradation of Methyl-Branched Alkanes by Mycobacterium sp. Strain P101

机译：α-甲基辅酶A消旋酶在分枝杆菌降解甲基支链烷烃中的作用。菌株P101

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A new isolate, Mycobacterium sp. strain P101, is capable of growth on methyl-branched alkanes (pristane, phytane, and squalane). Among ca. 10,000 Tn5-derived mutants, we characterized 2 mutants defective in growth on pristane or n-hexadecane. A single copy of Tn5 was found to be inserted into the coding region of mcr (α-methylacyl coenzyme A [α-methylacyl-CoA] racemase gene) in mutant P1 and into the coding region of mls (malate synthase gene) in mutant H1. Mutant P1 could not grow on methyl-branched alkanes. The recombinant Mcr produced in Escherichia coli was confirmed to catalyze racemization of (R)-2-methylpentadecanoyl-CoA, with a specific activity of 0.21 μmol?·?min?1?·?mg of protein?1. Real-time quantitative reverse transcriptase PCR analyses indicated that mcr gene expression was enhanced by the methyl-branched alkanes pristane and squalane. Mutant P1 used (S)-2-methylbutyric acid for growth but did not use the racemic compound, and growth on n-hexadecane was not inhibited by pristane. These results suggested that the oxidation of the methyl-branched alkanoic acid is inhibited by the (R) isomer, although the (R) isomer was not toxic during growth on n-hexadecane. Based on these results, Mcr is suggested to play a critical role in β-oxidation of methyl-branched alkanes in Mycobacterium. On the other hand, mutant H1 could not grow on n-hexadecane, but it partially retained the ability to grow on pristane. The reduced growth of mutant H1 on pristane suggests that propionyl-CoA is available for cell propagation through the 2-methyl citric acid cycle, since propionyl-CoA is produced through β-oxidation of pristane.
机译：一种新的分离物，分枝杆菌 sp。 P101菌株能够在甲基支链烷烃（rist烷，植烷和角鲨烷）上生长。约。 10,000个Tn 5 衍生的突变体，我们鉴定了2个在p烷或 n -十六烷上生长缺陷的突变体。发现单拷贝的Tn 5 插入突变体P1的 mcr （α-甲基酰基辅酶A [α-甲基酰基-CoA]消旋酶基因）的编码区中。并进入突变体H1的 mls （苹果酸合酶基因）编码区。突变体P1无法在甲基支链烷烃上生长。证实在大肠杆菌中产生的重组Mcr能够催化（ R ）-2-甲基十五碳酰辅酶A的消旋作用，比活度为0.21μmol？·minmin。 >？1 ？·？mg蛋白质？1 。实时定量逆转录酶PCR分析表明， mcr 基因表达被甲基支链烷烃rist烷和角鲨烷增强。突变体P1使用（ S ）-2-甲基丁酸进行生长，但不使用外消旋化合物，并且在 n -十六烷上的生长不受p烷的抑制。这些结果表明，尽管（ R ）异构体在的生长过程中无毒，但是（ R ）异构体抑制了甲基支链链烷酸的氧化。 > n -十六烷。基于这些结果，建议Mcr在分枝杆菌中的甲基支链烷烃的β-氧化中起关键作用。另一方面，突变体H1不能在 n -十六烷上生长，但部分保留了在p烷上生长的能力。突变体H1在rist烷上的生长减少表明丙酰辅酶A可通过2-甲基柠檬酸循环用于细胞繁殖，因为丙酰辅酶A是通过rist烷的β-氧化产生的。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

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