View source for 2cuo

[[Image:2cuo.gif|left|200px]]

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{{STRUCTURE_2cuo|  PDB=2cuo  |  SCENE=  }} 

'''Collagen model peptide (PRO-PRO-GLY)9'''


==Overview==
The crystal structure of a collagen-model peptide [(Pro-Pro-Gly)(9)](3) has been determined at 1.33 A resolution. Diffraction data were collected at 100 K using synchrotron radiation, which led to the first structural study of [(Pro-Pro-Gly)(n)](3) under cryogenic conditions. The crystals belong to the P2(1) space group with cell parameters of a = 25.95, b = 26.56, c = 80.14 Angstroms and beta = 90.0 degrees. The overall molecular conformation was consistent with the left-handed 7/2-helical model with an axial repeat of 20 A for native collagen. A total of 332 water molecules were found in an asymmetric unit. Proline residues in adjacent triple-helices exhibited three types of hydrophobic interactions. Furthermore, three types of hydrogen-bonding networks mediated by water molecules were observed between adjacent triple-helices. These hydrophobic interactions and hydrogen-bonding networks occurred at intervals of 20 Angstroms along the c-axis based on the previous sub-cell structures [(Pro-Pro-Gly)(n)](3) (n = 9, 10), which were also seen in the full-cell structure of [(Pro-Pro-Gly)(10)](3). Five proline residues at the Y position in the X-Y-Gly triplet were found in a down-puckering conformation, this being inconsistent with the recently proposed propensity-based hypothesis. These proline residues were forced to adopt opposing puckering because of the prevailing hydrophobic interaction between triple-helices compared with the Pro:Pro stacking interaction within a triple-helix.

==About this Structure==
Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2CUO OCA]. 

==Reference==
Repetitive interactions observed in the crystal structure of a collagen-model peptide, [(Pro-Pro-Gly)9]3., Hongo C, Noguchi K, Okuyama K, Tanaka Y, Nishino N, J Biochem. 2005 Aug;138(2):135-44. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/16091587 16091587]
[[Category: Hongo, C.]]
[[Category: Nishino, N.]]
[[Category: Noguchi, K.]]
[[Category: Okuyama, K.]]
[[Category: Tanaka, Y.]]
[[Category: Collagen model peptide]]
[[Category: Puckering]]
[[Category: Triple-helix]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 23:06:40 2008''