Complete sequence and model for the C1 subunit of the carotenoprotein crustacyanin, and model for the dimer, beta-crustacyanin, formed from the C1 and A2 subunits with astaxanthin
| Autor: | P.F. Zagalsky, John B. C. Findlay, Isabel Caceres, Jeffrey N. Keen, Elias Eliopoulos |
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| Rok vydání: | 1991 |
| Předmět: |
Models
Molecular Chemical Phenomena Molecular model Macromolecular Substances Protein Conformation Protein subunit Dimer Molecular Sequence Data Xanthophylls Biology Biochemistry chemistry.chemical_compound Complete sequence Astaxanthin Animals Amino Acid Sequence Binding site Binding Sites Chemistry Physical Binding protein Proteins beta Carotene Carotenoids Protein tertiary structure Nephropidae chemistry Carrier Proteins |
| Zdroj: | European Journal of Biochemistry. 202:31-40 |
| ISSN: | 1432-1033 0014-2956 |
| DOI: | 10.1111/j.1432-1033.1991.tb16340.x |
| Popis: | The complete sequence has been determined for the C1 subunit of crustacyanin, an astaxanthin-binding protein from the carapace of the lobster Homarus gammarus (L.). The polypeptide, 181 residues long, is similar (38% identity) to the other main subunit, A2 and to plasma retinol-binding protein. The tertiary structure of the C1 subunit has been modelled on that derived for the A2 subunit from the coordinates of retinol-binding protein. Residues lining the putative binding cavities and at the putative carotenoid binding sites of the two subunits are highly conserved. The carotenoid environments are characterized by a preponderance of aromatic and polar residues and the absence of charged side-chains. A tentative model for the dimer, beta-crustacyanin, formed between the two subunits with their associated carotenoid ligands, is discussed. The model is based on the crystal structure of the dimer of bilin-binding protein, a member of the same superfamily. This structure has enabled us to examine mechanisms for the bathochromic spectral shift of the protein-bound carotenoid and to identify likely contact regions between dimers in octameric alpha-crustacyanin. |
| Databáze: | OpenAIRE |
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