1aqp: Difference between revisions
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==Overview== | ==Overview== | ||
We report the crystal structures of the copper and nickel complexes of | 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 Structure== | ==About this Structure== | ||
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[[Category: hydrolase (phosphoric diester)]] | [[Category: hydrolase (phosphoric diester)]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:47:21 2008'' | ||
Revision as of 12:47, 21 February 2008
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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 as ligand. Active as Pancreatic ribonuclease, with EC number 3.1.27.5 Known structural/functional Site: . 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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