4cln
From Proteopedia
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STRUCTURE OF A RECOMBINANT CALMODULIN FROM DROSOPHILA MELANOGASTER REFINED AT 2.2-ANGSTROMS RESOLUTION
Overview
The crystal structure of calmodulin (Mr 16,700, 148 residues) from, Drosophila melanogaster as expressed in a bacterial system has been, determined and refined at 2.2-A resolution. Starting with the structure of, mammalian calmodulin, we produced an extensively refitted and refined, model with a conventional crystallographic R value of 0.197 for the 5,239, reflections (F greater than or equal to 2 sigma (F)) within the 10.0-2.2-A, resolution range. The model includes 1,164 protein atoms, 4 calcium ions, and 78 water molecules and has root mean square deviations from standard, values of 0.018 A for bond lengths and 0.043 A for angle distances. The, overall structure is similar to mammalian calmodulin, with a seven-turn, central helix connecting the two calcium-binding domains. The "dumb-bell", shaped molecule contains seven alpha-helices and four "EF hand", calcium-binding sites. Although the amino acid sequences of mammalian and, Drosophila calmodulins differ by only three conservative amino acid, changes, the refined model reveals a number of significant differences, between the two structures. Superimposition of the structures yields a, root mean square deviation of 1.22 A for the 1,120 equivalent atoms. The, calcium-binding domains have a root mean square deviation of 0.85 A for, the 353 equivalent atoms. There are also differences in the amino, terminus, the bend of the central alpha-helix, and the orientations of, some of the side chains.
About this Structure
4CLN is a Single protein structure of sequence from Drosophila melanogaster with CA as ligand. Full crystallographic information is available from OCA.
Reference
Structure of a recombinant calmodulin from Drosophila melanogaster refined at 2.2-A resolution., Taylor DA, Sack JS, Maune JF, Beckingham K, Quiocho FA, J Biol Chem. 1991 Nov 15;266(32):21375-80. PMID:1939171
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