Miyake M, Nagai H, Shirai M, Kurane R, Asada Y
National Institute of Bioscience and Human-Technology, Ministry of International Trade and Industry, Ibaraki, Japan.
Appl Biochem Biotechnol. 1999 Spring;77-79:267-75. doi: 10.1385/abab:77:1-3:267.
A 2.5 kb high-copy-number plasmid, pMA4 in thermophilic cyanobacterium Synechococcus sp. MA4 was isolated and characterized to develop a genetic engineering system for thermophilic cyanobacteria. The copy number of pMA4 was determined to be by densitometry about 350/cell. The pMA4 may be a type of rolling-circle plasmid, because a possible rep gene encoding 34 kD-protein and a consensus sequence of a double-stranded origin nick site of rolling circle plasmids were found in the pMA4 sequence. The pMA4 was electro-introduced into another thermophile, Synechococcus sp. MA19, which is the strongest poly-beta-hydroxybutyrate (PHB) accumulator in photoautotrophic organisms. The pMA4 was incorporated and retained in MA19. These results indicate that pMA4 could be developed as a useful vector for thermophilic cyanobacteria.
从嗜热蓝藻集胞藻属菌株MA4中分离并鉴定了一个2.5 kb的高拷贝质粒pMA4，以开发嗜热蓝藻的基因工程系统。通过密度测定法确定pMA4的拷贝数约为350个/细胞。pMA4可能是一种滚环质粒，因为在pMA4序列中发现了一个可能编码34 kD蛋白的rep基因以及滚环质粒双链起源切口位点的共有序列。将pMA4电导入另一种嗜热菌集胞藻属菌株MA19中，MA19是光合自养生物中最强的聚-β-羟基丁酸酯（PHB）积累者。pMA4被整合并保留在MA19中。这些结果表明pMA4可以被开发成为嗜热蓝藻的一种有用载体。
