Denis-Larose C, Bergeron H, Labbé D, Greer C W, Hawari J, Grossman M J, Sankey B M, Lau P C
Biotechnology Research Institute, National Research Council Canada, Montreal, Quebec, Canada H4P 2R2.
Appl Environ Microbiol. 1998 Nov;64(11):4363-7. doi: 10.1128/AEM.64.11.4363-4367.1998.
The replication region of a 100-kb desulfurization plasmid (pSOX) from Rhodococcus sp. strain X309 was localized to a 4-kb KpnI fragment, and its sequence was determined. The amino acid sequence of one of the predicted open reading frames (ORFs) was related to the putative replication (Rep) protein sequences of the mycobacterial pLR7 family of plasmids. Three of the five predicted ORF products were identified by radiolabelling with the Escherichia coli T7 polymerase/promoter system. In E. coli, the Rep protein of pSOX was apparently synthesized in a shortened form, 21.3 kDa instead of the predicted 41.3 kDa, as a result of an internal initiation. This situation is reminescent of that for some bacterial Rep proteins. A shuttle plasmid was constructed with the pSOX origin, pBluescript II KS-, and the chloramphenicol resistance (Cmr) gene from pRF29. This new shuttle plasmid was used to demonstrate expression of the Bacillus subtilis sacB gene in a strain of Rhodococcus, rendering it sensitive to the presence of sucrose.
来自红球菌属菌株X309的一个100 kb脱硫质粒（pSOX）的复制区域定位于一个4 kb的KpnI片段，并测定了其序列。预测的开放阅读框（ORF）之一的氨基酸序列与分枝杆菌属pLR7质粒家族假定的复制（Rep）蛋白序列相关。通过用大肠杆菌T7聚合酶/启动子系统进行放射性标记，鉴定了五个预测的ORF产物中的三个。在大肠杆菌中，由于内部起始，pSOX的Rep蛋白显然以缩短的形式合成，为21.3 kDa，而不是预测的41.3 kDa。这种情况让人想起一些细菌Rep蛋白的情况。用pSOX的复制起点、pBluescript II KS-和来自pRF29的氯霉素抗性（Cmr）基因构建了一个穿梭质粒。这个新的穿梭质粒用于证明枯草芽孢杆菌sacB基因在一株红球菌中的表达，使其对蔗糖的存在敏感。
