Chen C M, Misra T K, Silver S, Rosen B P
J Biol Chem. 1986 Nov 15;261(32):15030-8.
The structural genes for the arsenical pump of the conjugative R-factor R773 contained on a HindIII fragment of 4.3 kilobase pairs were cloned into bacteriophage M13. A series of ordered deletions was created using Bal31 digestion, and the nucleotide sequence of the operon determined. Three open reading frames for genes arsA, arsB, and arsC were found. The arsA gene encodes a hydrophilic protein of 63,169 Da with two potential adenylate-binding sites. The arsB gene encodes a potentially membrane protein of 45,577 Da. The arsC gene encodes a 15,811-Da hydrophilic protein. The arsA and arsC gene products correspond to cytosolic proteins previously identified from minicell experiments. Isolated ArsA protein was shown to bind to dye-agarose columns which act as affinity resins for nucleotide-binding proteins. A model is proposed in which these gene products form an anion translocating ATPase for extrusion of arsenite and arsenate from resistant cells.
结合性R因子R773的砷泵结构基因包含在一个4.3千碱基对的HindIII片段上，被克隆到噬菌体M13中。利用Bal31酶切产生了一系列有序缺失，并确定了操纵子的核苷酸序列。发现了arsA、arsB和arsC三个基因的开放阅读框。arsA基因编码一个63,169道尔顿的亲水性蛋白，带有两个潜在的腺苷酸结合位点。arsB基因编码一个45,577道尔顿的潜在膜蛋白。arsC基因编码一个15,811道尔顿的亲水性蛋白。arsA和arsC基因产物与先前从小细胞实验中鉴定出的胞质蛋白相对应。分离出的ArsA蛋白被证明能与染料琼脂糖柱结合，该柱作为核苷酸结合蛋白的亲和树脂。提出了一个模型，其中这些基因产物形成一个阴离子转运ATP酶，用于将亚砷酸盐和砷酸盐从抗性细胞中挤出。
