4ICB
PROLINE CIS-TRANS ISOMERS IN CALBINDIN D9K OBSERVED BY X-RAY CRYSTALLOGRAPHY
Summary for 4ICB
| Entry DOI | 10.2210/pdb4icb/pdb |
| Descriptor | CALBINDIN D9K, CALCIUM ION (3 entities in total) |
| Functional Keywords | calcium-binding protein |
| Biological source | Bos taurus (cattle) |
| Total number of polymer chains | 1 |
| Total formula weight | 8721.91 |
| Authors | Svensson, L.A. (deposition date: 1991-08-27, release date: 1993-10-31, Last modification date: 2024-02-28) |
| Primary citation | Svensson, L.A.,Thulin, E.,Forsen, S. Proline cis-trans isomers in calbindin D9k observed by X-ray crystallography. J.Mol.Biol., 223:601-606, 1992 Cited by PubMed Abstract: In a structure of recombinant bovine calbindin D9k, determined crystallographically to 1.6 A resolution, a proline in mixed, approximately equally populated, cis and trans conformation is observed. Isomers of this kind have not been reported in structure determinations of calbindin D9k to 2.3 A resolution or in any other crystallographically determined protein structure. The cis-trans isomerization occurs at the peptide bond between Gly42 and Pro43, which is in agreement with results from two-dimensional 1H nuclear magnetic resonance spectroscopy experiments on solutions of calbindin D9k. Alternative backbone stretches have been modeled and refined by stereochemical restrained least-squares refinement for the segment Lys41 to Pro43. The final R-value was 0.188. The structural perturbations accompanying the cis-trans isomerization are found to be very localized. The largest positional differences are observed at residue Gly42, in which the alternative positions of the oxygen atom are 3.6 A apart. PubMed: 1542107DOI: 10.1016/0022-2836(92)90976-Q PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.6 Å) |
Structure validation
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