Hickson I D, Gordon R L, Tomkinson A E, Emmerson P T
Mol Gen Genet. 1981;184(1):68-72. doi: 10.1007/BF00271197.
The temperature sensitive allele recA200 has been cloned into the multiple copy number plasmid pBR322 and the gene product isolated. The purified RecA200 protein is temperature sensitive in ability to cleave the phage lambda and LexA repressors in vitro and also in ability to promote a successful search for homology between single stranded DNA and a homologous duplex leading to D-loop formation. However, at the non-permissive temperature the RecA200 protein has approximately wild type single stranded DNA dependent ATPase activity and ability to promote pairing between homologous single DNA strands. The demonstration that the temperature sensitivity in vivo can be correlated with the temperature sensitive cleavage of the lambda and LexA repressors in vitro and also with D-loop formation shows that these in vitro reactions, which require large amounts of RecA protein, are not carried out by trace amounts of contaminating proteins.
温度敏感等位基因recA200已被克隆到多拷贝质粒pBR322中，并分离出了基因产物。纯化的RecA200蛋白在体外切割噬菌体λ和LexA阻遏物的能力以及促进单链DNA与同源双链之间成功寻找同源性以形成D环的能力方面对温度敏感。然而，在非允许温度下，RecA200蛋白具有近似野生型的单链DNA依赖性ATP酶活性以及促进同源单链DNA配对的能力。体内温度敏感性与体外λ和LexA阻遏物的温度敏感切割以及D环形成相关，这一证明表明，这些需要大量RecA蛋白的体外反应并非由痕量污染蛋白进行。
