1ym8: Difference between revisions

Revision as of 17:06, 21 February 2008

crystal structure of GZZ shows up puckering of the proline ring in the Xaa position.

OverviewOverview

The collagen triple helix is characterized by the repeating sequence motif Gly-Xaa-Yaa, where Xaa and Yaa are typically proline and (2S,4R)-4-hydroxyproline (4(R)Hyp), respectively. Previous analyses have revealed that H-(Pro-4(R)Hyp-Gly)(10)-OH forms a stable triple helix, whereas H-(4(R)Hyp-Pro-Gly)(10)-OH does not. Several theories have been put forth to explain the importance of proline puckering and conformation in triple helix formation; however, the details of how they affect triple helix stability are unknown. Underscoring this, we recently demonstrated that the polypeptide Ac-(Gly-4(R)Hyp-4(R)Hyp)(10)-NH(2) forms a triple helix that is more stable than Ac-(Gly-Pro-4(R)Hyp)(10)-NH(2). Here we report crystal the structure of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide at 1.55 A resolution. The puckering of the Yaa position 4(R)Hyp in this structure is up (Cgamma exo), as has been found in other collagen peptide structures. Notably, however, the 4(R)Hyp in the Xaa position also takes the up pucker, which is distinct from all other collagen structures. Regardless of the notable difference in the Xaa proline puckering, our structure still adopts a 7/2 superhelical symmetry similar to that observed in other collagen structures. Thus, the basis for the observed differences in the thermodynamic data of the triple helix<--> coil transition between our peptide and other triple helical peptides likely results from contributions from the unfolded state. Indeed, the unfolded state of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide seems to be stabilized by a preformed polyproline II helix in each strand, which could be explained by the presence of a unique repeating intra-strand water-mediated bridge observed in the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH structure, as well as a higher amount of trans peptide bonds.

About this StructureAbout this Structure

1YM8 is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.

ReferenceReference

The crystal structure of the collagen-like polypeptide (glycyl-4(R)-hydroxyprolyl-4(R)-hydroxyprolyl)9 at 1.55 A resolution shows up-puckering of the proline ring in the Xaa position., Schumacher M, Mizuno K, Bachinger HP, J Biol Chem. 2005 May 27;280(21):20397-403. Epub 2005 Mar 22. PMID:15784619

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-[[Image:1ym8.gif|left|200px]]<br /><applet load="1ym8" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1ym8.gif|left|200px]]<br /><applet load="1ym8" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1ym8, resolution 1.55&Aring;" />
 '''crystal structure of GZZ shows up puckering of the proline ring in the Xaa position.'''<br />
 ==Overview==
-The collagen triple helix is characterized by the repeating sequence motif, Gly-Xaa-Yaa, where Xaa and Yaa are typically proline and, (2S,4R)-4-hydroxyproline (4(R)Hyp), respectively. Previous analyses have, revealed that H-(Pro-4(R)Hyp-Gly)(10)-OH forms a stable triple helix, whereas H-(4(R)Hyp-Pro-Gly)(10)-OH does not. Several theories have been, put forth to explain the importance of proline puckering and conformation, in triple helix formation; however, the details of how they affect triple, helix stability are unknown. Underscoring this, we recently demonstrated, that the polypeptide Ac-(Gly-4(R)Hyp-4(R)Hyp)(10)-NH(2) forms a triple, helix that is more stable than Ac-(Gly-Pro-4(R)Hyp)(10)-NH(2). Here we, report crystal the structure of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide, at 1.55 A resolution. The puckering of the Yaa position 4(R)Hyp in this, structure is up (Cgamma exo), as has been found in other collagen peptide, structures. Notably, however, the 4(R)Hyp in the Xaa position also takes, the up pucker, which is distinct from all other collagen structures., Regardless of the notable difference in the Xaa proline puckering, our, structure still adopts a 7/2 superhelical symmetry similar to that, observed in other collagen structures. Thus, the basis for the observed, differences in the thermodynamic data of the triple helix&lt;--&gt; coil, transition between our peptide and other triple helical peptides likely, results from contributions from the unfolded state. Indeed, the unfolded, state of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide seems to be stabilized, by a preformed polyproline II helix in each strand, which could be, explained by the presence of a unique repeating intra-strand, water-mediated bridge observed in the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH, structure, as well as a higher amount of trans peptide bonds.
+The collagen triple helix is characterized by the repeating sequence motif Gly-Xaa-Yaa, where Xaa and Yaa are typically proline and (2S,4R)-4-hydroxyproline (4(R)Hyp), respectively. Previous analyses have revealed that H-(Pro-4(R)Hyp-Gly)(10)-OH forms a stable triple helix, whereas H-(4(R)Hyp-Pro-Gly)(10)-OH does not. Several theories have been put forth to explain the importance of proline puckering and conformation in triple helix formation; however, the details of how they affect triple helix stability are unknown. Underscoring this, we recently demonstrated that the polypeptide Ac-(Gly-4(R)Hyp-4(R)Hyp)(10)-NH(2) forms a triple helix that is more stable than Ac-(Gly-Pro-4(R)Hyp)(10)-NH(2). Here we report crystal the structure of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide at 1.55 A resolution. The puckering of the Yaa position 4(R)Hyp in this structure is up (Cgamma exo), as has been found in other collagen peptide structures. Notably, however, the 4(R)Hyp in the Xaa position also takes the up pucker, which is distinct from all other collagen structures. Regardless of the notable difference in the Xaa proline puckering, our structure still adopts a 7/2 superhelical symmetry similar to that observed in other collagen structures. Thus, the basis for the observed differences in the thermodynamic data of the triple helix&lt;--&gt; coil transition between our peptide and other triple helical peptides likely results from contributions from the unfolded state. Indeed, the unfolded state of the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH peptide seems to be stabilized by a preformed polyproline II helix in each strand, which could be explained by the presence of a unique repeating intra-strand water-mediated bridge observed in the H-(Gly-4(R)Hyp-4(R)Hyp)(9)-OH structure, as well as a higher amount of trans peptide bonds.
 ==About this Structure==
-YM8 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1YM8 OCA].
+YM8 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/ ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1YM8 OCA].
 ==Reference==
 The crystal structure of the collagen-like polypeptide (glycyl-4(R)-hydroxyprolyl-4(R)-hydroxyprolyl)9 at 1.55 A resolution shows up-puckering of the proline ring in the Xaa position., Schumacher M, Mizuno K, Bachinger HP, J Biol Chem. 2005 May 27;280(21):20397-403. Epub 2005 Mar 22. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=15784619 15784619]
 [[Category: Protein complex]]
-[[Category: Bachinger, H.P.]]
+[[Category: Bachinger, H P.]]
 [[Category: Mizuno, K.]]
-[[Category: Schumacher, M.A.]]
+[[Category: Schumacher, M A.]]
 [[Category: collagen; triple helix; proline pucker]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 04:20:40 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:06:46 2008''