一株动性球菌ZOYM的初步鉴定及其内源性质粒pPCZ1和pPCZ2的分析

Identification of a New Planococcus Strain and Analysis of Its Indigenous Plasmids pPCZ1 and pPCZ2

摘要:

从来自中国深海的样品中分离到一株菌株ZOYM, PCR获得其16S rRNA基因序列, 经比对, 与已发表的动性球菌属(Planococcus)的不同种高度相似。提取质粒DNA, 在琼脂糖凝胶上检测到多条DNA带, 对其中2个小的环型质粒pPCZ1和pPCZ2进行了克隆和测序。 pPCZ1和pPCZ2的全长分别为4738 bp和7935 bp, 编码3个和8个蛋白。预测的pPCZ1和pPCZ2的复制蛋白Rep分别与链球菌(Staphylococcus)质粒pSCFS1和芽孢杆菌(Bacillus) 质粒pBM19的Rep有很高的相似性。此外, pPCZ1和pPCZ2的复制蛋白Rep之间也有一定的同源性。质粒pPCZ1和pPCZ2上均未找到滚环复制质粒保守的dso和sso序列, 而在复制基因的上游均发现有多个重复序列和富含AT的序列, 因此, 推测它们可能不是以滚环方式进行复制, 而是theta方式。这是首次报道动性球菌属两个质粒的完整序列。

Abstract:

A new strain ZOYM was isolated from deep ocean of China and its 16S rRNA gene sequence showed high homology with that of the other published Planococcus species. Plasmids DNA were isolated and multiple bands were detected on an agarose gel, and two small of them, designated pPCZ1 and pPCZ2, were further cloned and sequenced. The complete nucleotide sequences of pPCZ1 and pPCZ2 consisted of 4738 and 7975 base pairs, encoding 3 and 8 proteins, respectively. The predicted replication proteins (Reps) of pPCZ1 and pPCZ2 showed high homology with that of Staphylococcus plasmid pSCFS1 and Bacillus plasmid pBM19, respectively. In additional, the Reps of pPCZ1 and pPCZ2 displayed homology with each other. No conserved dso and sso of the rolling-circle plasmids were found on pPCZ1 and pPCZ2, while multiple direct-repeats and AT-rich sequences were found on upstream of the rep genes, suggesting that replication of the two plasmids might be in a mechanism of theta-type. This is first report on the complete nucleotide sequences of Planococcus plasmids pPCZ1 and pPCZ2.