Distribution of megaplasmids in Lactobacillus salivarius and other Lactobacilli
Distribution of megaplasmids in Lactobacillus salivarius and other Lactobacilli
复制标题
DOI：
10.1128/jb.00447-07
复制
发表时间：
2007-09-01
影响因子：
3.2
通讯作者：
O'Toole, Paul W.
中科院分区：
文献类型：
--
作者：
Li, Yin;Canchaya, Carlos;O'Toole, Paul W.
唾液乳杆菌UCC118的基因组包括一个242kb的巨质粒pMP118。我们现在发现，从人和动物中分离的33株唾液酸链球菌都含有一个巨质粒，它与pMP118的REPA和REPE复制起始探针杂交。在一些菌株中也发现了不与pMP118REPA探针杂交的线性巨质粒，首次表明一株乳酸菌具有多个巨质粒。对28株唾液酸链霉菌的epE和GroEL序列的系统发育分析表明，染色体和巨质粒具有相似的进化路径。虽然环状巨质粒在唾液酸菌中的复制来源是高度保守的，但基因型别和表型比较揭示了巨型质粒编码性状之间的显著差异。此外，在所检测的91株乳杆菌和47种乳杆菌中，有7株属于其他6个乳杆菌种，大小从120 kb到490 kb不等。在唾液乳杆菌中广泛存在的巨质粒的发现，以及其他乳杆菌限制携带的发现，为研究大型染色体外复制子对乳杆菌生物学的贡献提供了机会。
The genome of Lactobacillus salivarius UCC118 includes a 242-kb megaplasmid, pMP118. We now show that 33 strains of L. salivarius isolated from humans and animals all harbor a megaplasmid, which hybridized with the repA and repE replication origin probes of pMP118. Linear megaplasmids that did not hybridize with the pMP118 repA probe were also found in some strains of L. salivarius, showing for the first time that a lactic acid bacterium has multiple megaplasmids. Phylogenetic analysis of the repE and groEL sequences of 28 L. salivarius strains suggested similar evolutionary paths for the chromosome and megaplasmid. Although the replication origin of circular megaplasmids in L. salivarius was highly conserved, genotypic and phenotypic comparisons revealed significant variation between megaplasmid-encoded traits. Furthermore, megaplasmids of sizes ranging from 120 kb to 490 kb were present in seven strains belonging to six other Lactobacillus species from among 91 strains and 47 species tested. The discovery of the widespread presence of megaplasmids in L. salivarius, and restricted carriage by other Lactobacillus species, provides an opportunity to study the contribution of large extrachromosomal replicons to the biology of Lactobacillus.