Reece R J, Maxwell A
Department of Biochemistry, University of Leicester, UK.
Nucleic Acids Res. 1991 Apr 11;19(7):1399-405. doi: 10.1093/nar/19.7.1399.
We have constructed a clone which over-produces a 33 kDa protein representing the C-terminal portion of the Escherichia coli DNA gyrase A subunit. This protein has no enzymic activity of its own, but will form a complex with a 64 kDa protein (representing the N-terminal part of the A subunit) and the gyrase B subunit, that will efficiently catalyse DNA supercoiling. We show that the 33 kDa protein can bind to DNA on its own in a manner which induces positive supercoiling of the DNA. We propose that the 33 kDa protein represents a domain of the gyrase A subunit which is involved in the wrapping of DNA around DNA gyrase.
我们构建了一个克隆体，它过量产生一种33 kDa的蛋白质，该蛋白质代表大肠杆菌DNA促旋酶A亚基的C末端部分。这种蛋白质自身没有酶活性，但会与一种64 kDa的蛋白质（代表A亚基的N末端部分）和促旋酶B亚基形成复合物，该复合物能高效催化DNA超螺旋化。我们发现，33 kDa的蛋白质自身能够以一种诱导DNA正超螺旋化的方式与DNA结合。我们提出，33 kDa的蛋白质代表促旋酶A亚基的一个结构域，该结构域参与DNA围绕DNA促旋酶的缠绕过程。
