Sequence analysis of mutA and mutM genes involved in the biosynthesis of the lantibiotic mutacin II in Streptococcus mutans.
Sequence analysis of mutA and mutM genes involved in the biosynthesis of the lantibiotic mutacin II in Streptococcus mutans.
复制标题
DOI：
10.1016/s0378-1119(97)00578-7
复制
发表时间：
1998-01
期刊：
影响因子：
3.5
通讯作者：
Wendy A. Woodruff;Jan Novak;P. Caufield
中科院分区：
文献类型：
--
作者：
Wendy A. Woodruff;Jan Novak;P. Caufield
变形链球菌与许多其他革兰氏阳性细菌一起产生称为细菌素的小抗菌肽。由变异链球菌产生的细菌素（称为变异素）可以提供这种主要牙科病原体在牙菌斑中初始或持续定植所必需的选择力。此前，我们纯化并表征了 mutacin II，这是在变形链球菌中发现的第一种羊毛硫抗生素。根据 N 端氨基酸序列设计的特定寡核苷酸允许使用单特异性引物 PCR (SSP-PCR) 扩增 N 端上游 0.7kb 和下游 2.1kb。随后对编码突变蛋白 II 前肽 mutA 的基因进行了克隆和测序。完整的前肽由 53 个氨基酸组成，包括 26 个氨基酸的两亲性前导肽，在加工位点具有 Gly−2–Gly−1 序列。该前肽与羊毛硫抗生素乳酸菌素 481、variacin、salivaricin 和链球菌素 A-FF22 相似。紧邻 mutA 下游的 3kb 开放阅读框（表示为 mutM）显示出与乳酸乳球菌 LCNDR2 的序列相似性。以此类推，mutM可能参与了突变蛋白前肽的翻译后修饰。使用插入载体 pVA891 进行的基因破坏表明，mutA 和 mutM 的完整拷贝是生产 mutacin II 所必需的。
Streptococcus mutans, along with many other Gram-positive bacteria produce small antibacterial peptides called bacteriocins. Bacteriocins elaborated by S. mutans, termed mutacins, may provide a selective force necessary for initial or sustained colonization in dental plaque by this major dental pathogen. Previously, we purified and characterized mutacin II, the first lantibiotic found in S. mutans. Specific oligonucleotides designed according to the N-terminal amino acid sequence permitted amplification of 0.7kb upstream and 2.1kb downstream of the N-terminus, using single-specific-primer PCR (SSP–PCR). The gene encoding the mutacin II prepeptide, mutA, was subsequently cloned and sequenced. The complete prepeptide consists of 53 amino acids, including the 26 amino acid amphipathic leader peptide with the Gly−2–Gly−1sequence at the processing site. The prepeptide showed similarity to the lantibiotics lacticin 481, variacin, salivaricin and streptococcin A-FF22. A 3kb open reading frame immediately downstream of mutA, denoted mutM, showed sequence similarities to LCNDR2 from Lactococcus lactis. By analogy, mutM is probably involved in post-translational modification of the mutacin prepeptide. Gene disruption with an insertional vector pVA891 showed that intact copies of mutA and mutM are required for production of mutacin II.