First time at Proteopedia? Click on the green links: they change the 3D image. Click and drag the molecules. Proteopedia is a 3D, interactive encyclopedia of proteins, RNA, DNA and other molecules. With a free user account, you can edit pages in Proteopedia. Visit the Main Page to learn more.
5cpa
From Proteopedia
| 5cpa, resolution 1.54Å () | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Ligands: | |||||||||
| Activity: | Carboxypeptidase A, with EC number 3.4.17.1 | ||||||||
| |||||||||
| |||||||||
| Resources: | FirstGlance, OCA, RCSB, PDBsum | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
Contents |
REFINED CRYSTAL STRUCTURE OF CARBOXYPEPTIDASE A AT 1.54 ANGSTROMS RESOLUTION.
The crystal structure of bovine carboxypeptidase A (Cox) has been refined at 1.54 A resolution using the restrained least-squares algorithm of Hendrickson & Konnert (1981). The crystallographic R factor (formula; see text) for structure factors calculated from the final model is 0.190. Bond lengths and bond angles in the carboxypeptidase A model have root-mean-square deviations from ideal values of 0.025 A and 3.6 degrees, respectively. Four examples of a reverse turn like structure (the "Asx" turn) requiring an aspartic acid or asparagine residue are observed in this structure. The Asx turn has the same number of atoms as a reverse turn, but only one peptide bond, and the hydrogen bond that closes the turn is between the Asx side-chain CO group and a main-chain NH group. The distributions of CO-N and NH-O hydrogen bond angles in the alpha-helices and beta-sheet structures of carboxypeptidase A are centered about 156 degrees. A total of 192 water molecules per molecule of enzyme are included in the final model. Unlike the hydrogen bonding geometry observed in the secondary structure of the enzyme, the CO-O(wat) hydrogen bond angle is distributed about 131 degrees, indicating the role of the lone pair electrons of the carbonyl oxygen in the hydrogen bond interaction. Twenty four solvent molecules are observed buried within the protein. Several of these waters are organized into hydrogen-bonded chains containing up to five waters. The average temperature factor for atoms in carboxypeptidase A is 8 A2, and varies from 5 A2 in the center of the protein, to over 30 A2 at the surface.
Refined crystal structure of carboxypeptidase A at 1.54 A resolution., Rees DC, Lewis M, Lipscomb WN, J Mol Biol. 1983 Aug 5;168(2):367-87. PMID:6887246
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
5cpa is a 1 chain structure with sequence from Bos taurus. Full crystallographic information is available from OCA.
See Also
Reference
- Rees DC, Lewis M, Lipscomb WN. Refined crystal structure of carboxypeptidase A at 1.54 A resolution. J Mol Biol. 1983 Aug 5;168(2):367-87. PMID:6887246
