嘌呤阻遏物DNA结合结构域与DNA复合时的构象变化。

Conformational changes of purine repressor DNA-binding domain upon complexation with DNA.

作者信息

Nagadoi A, Nakazawa K, Morikawa S, Nakamura H, Sampei G, Mizobuchi K, Yamamoto H, Schumacher M A, Brennan R G, Nishimura Y

机构信息

Graduate School of Integrated Science, Yokohama City University, Japan.

出版信息

Nucleic Acids Symp Ser. 1995(34):63-4.

PMID:8841553

Abstract

The purine repressor (PurR) consists of two functional domains: an N-terminal DNA-binding domain and a C-terminal corepressor-binding domain. Recently, the structure of PurR-corepressor-operator ternary complex was determined by X-ray crystallography. In the complex the DNA-binding domain, consisting of 56 amino acids, was composed of four helices. Here, we have determined the solution structure of the DNA-binding domain in its DNA free state by NMR. It consists of three helices and the fourth helix (the hinge helix) region is diordered. The architecture of the first three helices of its DNA free state is very similar to that of its DNA-bound form. The hinge helix is induced by the specific DNA binding and by the dimerization of PurR which is provided by the corepressor-binding domain.

摘要

嘌呤阻遏蛋白（PurR）由两个功能结构域组成：一个N端DNA结合结构域和一个C端共阻遏物结合结构域。最近，通过X射线晶体学确定了PurR-共阻遏物-操纵子三元复合物的结构。在该复合物中，由56个氨基酸组成的DNA结合结构域由四个螺旋组成。在此，我们通过核磁共振确定了处于无DNA状态的DNA结合结构域的溶液结构。它由三个螺旋组成，第四个螺旋（铰链螺旋）区域无序。其无DNA状态下前三个螺旋的结构与结合DNA状态下的结构非常相似。铰链螺旋是由特定的DNA结合以及由共阻遏物结合结构域提供的PurR二聚化诱导产生的。