1cag

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spinqualitylabelsall models 1cag, resolution 1.85Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL AND MOLECULAR STRUCTURE OF A COLLAGEN-LIKE PEPTIDE AT 1.9 ANGSTROM RESOLUTION

Overview

The structure of a protein triple helix has been determined at 1.9, angstrom resolution by x-ray crystallographic studies of a collagen-like, peptide containing a single substitution of the consensus sequence. This, peptide adopts a triple-helical structure that confirms the basic features, determined from fiber diffraction studies on collagen: supercoiling of, polyproline II helices and interchain hydrogen bonding that follows the, model II of Rich and Crick. In addition, the structure provides new, information concerning the nature of this protein fold. Each triple helix, is surrounded by a cylinder of hydration, with an extensive hydrogen, bonding network between water molecules and peptide acceptor groups., Hydroxyproline residues have a critical role in this water network. The, interaxial spacing of triple helices in the crystal is similar to that in, collagen fibrils, and the water networks linking adjacent triple helices, in the crystal structure are likely to be present in connective tissues., The breaking of the repeating (X-Y-Gly)n pattern by a Gly-->Ala, substitution results in a subtle alteration of the conformation, with a, local untwisting of the triple helix. At the substitution site, direct, interchain hydrogen bonds are replaced with interstitial water bridges, between the peptide groups. Similar conformational changes may occur in, Gly-->X mutated collagens responsible for the diseases osteogenesis, imperfecta, chondrodysplasias, and Ehlers-Danlos syndrome IV.

About this Structure

1CAG is a Protein complex structure of sequences from [1] with ACY as ligand. The following page contains interesting information on the relation of 1CAG with [Collagen]. Full crystallographic information is available from OCA.

Reference

Crystal and molecular structure of a collagen-like peptide at 1.9 A resolution., Bella J, Eaton M, Brodsky B, Berman HM, Science. 1994 Oct 7;266(5182):75-81. PMID:7695699

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