The structure of a DNA unwinding protein and its complexes with oligodeoxynucleotides by x-ray diffraction

A. McPherson, F. Jurnak, A. Wang, F. Kolpak, A. Rich, I. Molineux, P. Fitzgerald

研究成果: 雜誌貢獻文章同行評審

32 引文 斯高帕斯(Scopus)

摘要

The structure of the gene 5 DNA unwinding protein from bacteriophage fd has been solved to 2.3 A resolution by x-ray diffraction techniques. The molecule contains an extensive cleft region that we have identified as the DNA binding site on the basis of the residues that comprise its surface. The interior of the groove has a rather large number of basic amino acid residues that serve to draw the polynucleotide backbone into the cleft. Arrayed along the external edges of the groove are a number of aromatic amino acid side groups that are in position to stack upon the bases of the DNA and fix it in place. The cleft then acts as an elongated pair of jaws that draws the DNA between them by charge interactions involving the phosphates with the interior lysines and arginines. The jaws then close on the DNA strand through small conformation changes and the rotation of aromatic side-chains into position to stack upon the purines and pyrimidines. Complexes of the gene 5 protein with a variety of oligodeoxynucleotides have been formed and crystallized for x-ray diffraction analysis. The crystallographic parameters of four different unit cells indicate that the fundamental unit of the complex is composed of six gene 5 protein dimers. We believe this aggregate has 622 point group symmetry and is a ring formed by end to end closure of a linear array of six dimers. From our results we have proposed a double helical model for the gene 5 protein-DNA complex in which the protein forms a spindle or core around which the DNA is spooled. 5.0-A x-ray diffraction data from one of the crystalline complexes is currently being analyzed by molecular replacement techniques to obtain what we believe will be the first direct visualization of a protein-deoxyribonucleic acid complex approaching atomic resolution.

原文英語
頁(從 - 到)155-173
頁數19
期刊Biophysical Journal
32
發行號1
DOIs
出版狀態已發佈 - 1980
對外發佈

ASJC Scopus subject areas

  • 生物物理學

指紋

深入研究「The structure of a DNA unwinding protein and its complexes with oligodeoxynucleotides by x-ray diffraction」主題。共同形成了獨特的指紋。

引用此