1aqp

File:1aqp.gif

spinqualitylabelsall models 1aqp, resolution 2.0Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

RIBONUCLEASE A COPPER COMPLEX

OverviewOverview

We report the crystal structures of the copper and nickel complexes of, RNase A. The overall topology of these two complexes is similar to that of, other RNase A structures. However, there are significant differences in, the mode of binding of copper and nickel. There are two copper ions per, molecule of the protein, but there is only one nickel ion per molecule of, the protein. Significant changes occur in the interprotein interactions as, a result of differences in the coordinating groups at the common binding, site around His-105. Consequently, the copper- and nickel-ion-bound dimers, of RNase A act as nucleation sites for generating different crystal, lattices for the two complexes. A second copper ion is present at an, active site residue His-119 for which all the ligands are from one, molecule of the protein. At this second site, His-119 adopts an inactive, conformation (B) induced by the copper. We have identified a novel copper, binding motif involving the alpha-amino group and the N-terminal residues.

About this StructureAbout this Structure

1AQP is a Single protein structure of sequence from Bos taurus with CU as ligand. Active as Pancreatic ribonuclease, with EC number 3.1.27.5 Structure known Active Sites: and CII. Full crystallographic information is available from OCA.

ReferenceReference

Crystal structures of the copper and nickel complexes of RNase A: metal-induced interprotein interactions and identification of a novel copper binding motif., Balakrishnan R, Ramasubbu N, Varughese KI, Parthasarathy R, Proc Natl Acad Sci U S A. 1997 Sep 2;94(18):9620-5. PMID:9275172

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