Crystal structure of the collagen triple helix model [(Pro-Pro-Gly)(10)](3).
The first report of the full-length structure of the collagen-like polypeptide [(Pro-Pro-Gly)(10)](3) is given. This structure was obtained from crystals grown in a microgravity environment, which diffracted up to 1.3 A, using synchrotron radiation. The final model, which was refined to an R(factor) of 0.18, is the highest-resolution description of a collagen triple helix reported to date. This structure provides clues regarding a series of aspects related to collagen triple helix structure and assembly. The strict dependence of proline puckering on the position inside the Pro-Pro-Gly triplets and the correlation between backbone and side chain dihedral angles support the propensity-based mechanism of triple helix stabilization/destabilization induced by hydroxyproline. Furthermore, the analysis of [(Pro-Pro-Gly)(10)](3) packing, which is governed by electrostatic interactions, suggests that charges may act as locking features in the axial organization of triple helices in the collagen fibrils.
Berisio
Rita
R
Centro di Studio di Biocristallografia, CNR, I-80134 Napoli, Italy.
Vitagliano
Luigi
L
Mazzarella
Lelio
L
Zagari
Adriana
A
D003094:Collagen / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D005998:Glycine; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011392:Proline; D011487:Protein Conformation
D009842:Oligopeptides; D010455:Peptides; C044555:prolyl-prolyl-glycine; D003094:Collagen; D011392:Proline; D005998:Glycine