3psg
From Proteopedia
(New page: 200px<br /> <applet load="3psg" size="450" color="white" frame="true" align="right" spinBox="true" caption="3psg, resolution 1.65Å" /> '''THE HIGH RESOLUTION...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:3psg.gif|left|200px]]<br /> | + | [[Image:3psg.gif|left|200px]]<br /><applet load="3psg" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="3psg" size=" | + | |
caption="3psg, resolution 1.65Å" /> | caption="3psg, resolution 1.65Å" /> | ||
'''THE HIGH RESOLUTION CRYSTAL STRUCTURE OF PORCINE PEPSINOGEN'''<br /> | '''THE HIGH RESOLUTION CRYSTAL STRUCTURE OF PORCINE PEPSINOGEN'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The structure of porcine pepsinogen at pH 6.1 has been refined to an | + | The structure of porcine pepsinogen at pH 6.1 has been refined to an R-factor of 0.173 for data extending to 1.65 A. The final model contains 180 solvent molecules and lacks density for residues 157-161. The structure of this aspartic proteinase zymogen possesses many of the characteristics of pepsin, the mature enzyme. The secondary structure of the zymogen consists predominantly of beta-sheet, with an approximate 2-fold axis of symmetry. The activation peptide packs into the active site cleft, and the N-terminus (1P-9P) occupies the position of the mature N-terminus (1-9). Thus changes upon activation include excision of the activation peptide and proper relocation of the mature N-terminus. The activation peptide or residues of the displaced mature N-terminus make specific interactions with the substrate binding subsites. The active site of pepsinogen is intact; thus the lack of activity of pepsinogen is not due to a deformation of the active site. Nine ion pairs in pepsinogen may be important in the advent of activation and involve the activation peptide or regions of the mature N-terminus which are relocated in the mature enzyme. The activation peptide-pepsin junction, 44P-1, is characterized by high thermal parameters and weak density, indicating a flexible structure which would be accessible to cleavage. Pepsinogen is an appropriate model for the structures of other zymogens in the aspartic proteinase family. |
==About this Structure== | ==About this Structure== | ||
| - | 3PSG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. This structure | + | 3PSG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. This structure supersedes the now removed PDB entry 1PSG. The following page contains interesting information on the relation of 3PSG with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb12_1.html Pepsin]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3PSG OCA]. |
==Reference== | ==Reference== | ||
| Line 15: | Line 14: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Sus scrofa]] | [[Category: Sus scrofa]] | ||
| - | [[Category: Hartsuck, J | + | [[Category: Hartsuck, J A.]] |
[[Category: Koelsch, G.]] | [[Category: Koelsch, G.]] | ||
| - | [[Category: Remington, S | + | [[Category: Remington, S J.]] |
[[Category: hydrolase(acid proteinase zymogen)]] | [[Category: hydrolase(acid proteinase zymogen)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 19:10:58 2008'' |
Revision as of 17:11, 21 February 2008
|
THE HIGH RESOLUTION CRYSTAL STRUCTURE OF PORCINE PEPSINOGEN
Overview
The structure of porcine pepsinogen at pH 6.1 has been refined to an R-factor of 0.173 for data extending to 1.65 A. The final model contains 180 solvent molecules and lacks density for residues 157-161. The structure of this aspartic proteinase zymogen possesses many of the characteristics of pepsin, the mature enzyme. The secondary structure of the zymogen consists predominantly of beta-sheet, with an approximate 2-fold axis of symmetry. The activation peptide packs into the active site cleft, and the N-terminus (1P-9P) occupies the position of the mature N-terminus (1-9). Thus changes upon activation include excision of the activation peptide and proper relocation of the mature N-terminus. The activation peptide or residues of the displaced mature N-terminus make specific interactions with the substrate binding subsites. The active site of pepsinogen is intact; thus the lack of activity of pepsinogen is not due to a deformation of the active site. Nine ion pairs in pepsinogen may be important in the advent of activation and involve the activation peptide or regions of the mature N-terminus which are relocated in the mature enzyme. The activation peptide-pepsin junction, 44P-1, is characterized by high thermal parameters and weak density, indicating a flexible structure which would be accessible to cleavage. Pepsinogen is an appropriate model for the structures of other zymogens in the aspartic proteinase family.
About this Structure
3PSG is a Single protein structure of sequence from Sus scrofa. This structure supersedes the now removed PDB entry 1PSG. The following page contains interesting information on the relation of 3PSG with [Pepsin]. Full crystallographic information is available from OCA.
Reference
The high-resolution crystal structure of porcine pepsinogen., Hartsuck JA, Koelsch G, Remington SJ, Proteins. 1992 May;13(1):1-25. PMID:1594574
Page seeded by OCA on Thu Feb 21 19:10:58 2008
