Macrina F L, Tobian J A, Jones K R, Evans R P, Clewell D B
Gene. 1982 Oct;19(3):345-53. doi: 10.1016/0378-1119(82)90025-7.
A plasmid that is able to replicate in both Escherichia coli and Streptococcus sanguis has been constructed by the in vitro joining of the pACYC184 (Cmr Tcr) and pVA749 (Emr) replicons. This plasmid, designated pVA838, is 9.2 kb in size and expresses Emr in both E. coli and S. sanguis. Its Cmr marker is expressed only in E. coli and may be inactivated by addition of DNA inserts at its internal EcoRI or PvuII sites. The pVA838 molecule also contains unique SalI, SphI, BamHI, NruI and XbaI cleavage sites suitable for molecular cloning. pVA838 may be amplified in E. coli but not in S. sanguis. We have used the pVA838 plasmid as a shuttle vector to clone streptococcal plasmid fragments in E. coli. Such chimeras isolated from E. coli were readily introduced into S. sanguis by transformation.
通过体外连接pACYC184（Cmr Tcr）和pVA749（Emr）复制子，构建了一种能够在大肠杆菌和血链球菌中复制的质粒。这种质粒命名为pVA838，大小为9.2 kb，在大肠杆菌和血链球菌中均表达Emr。其Cmr标记仅在大肠杆菌中表达，并且可通过在其内部EcoRI或PvuII位点添加DNA插入片段而失活。pVA838分子还包含适合分子克隆的独特SalI、SphI、BamHI、NruI和XbaI切割位点。pVA838可在大肠杆菌中扩增，但不能在血链球菌中扩增。我们已将pVA838质粒用作穿梭载体，在大肠杆菌中克隆链球菌质粒片段。从大肠杆菌中分离出的此类嵌合体可通过转化轻易导入血链球菌。
