Jump to: Page Content, Section Navigation, Site Navigation, Site Search, Account Information, or Site Tools.
|
|
ArticlesCopyright © 1986 by American Association for the Advancement of Science
The mechanism of binding of a polynucleotide chain to pancreatic ribonuclease
The crystalline complex of pancreatic ribonuclease (RNase) with oligomers of d(pA)4 has been solved by x-ray diffraction methods and refined by standard procedures to a conventional crystallographic R factor of 0.22 at 2.5 angstrom resolution. The asymmetric unit is a complex of one RNase molecule associated with four d(pA)4 oligomers. Although the DNA in this complex is segmented, and therefore shows some discontinuities, it nevertheless traces a continuous path 12 nucleotides in length that passes through the active site cleft of the enzyme and over the surface of the protein. The DNA makes a series of eight to nine electrostatic bonds between its phosphate groups and lysine and arginine residues on the protein, as well as specific chemical interactions at the active site. The path described by the sequence of nucleotides is likely to be that taken by an extended polynucleotide chain when it is bound by the enzyme.
THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
|
Science. ISSN 0036-8075 (print), 1095-9203 (online)