1lop
From Proteopedia
| Line 1: | Line 1: | ||
[[Image:1lop.gif|left|200px]] | [[Image:1lop.gif|left|200px]] | ||
| - | + | <!-- | |
| - | + | The line below this paragraph, containing "STRUCTURE_1lop", creates the "Structure Box" on the page. | |
| - | + | You may change the PDB parameter (which sets the PDB file loaded into the applet) | |
| - | + | or the SCENE parameter (which sets the initial scene displayed when the page is loaded), | |
| - | + | or leave the SCENE parameter empty for the default display. | |
| - | | | + | --> |
| - | | | + | {{STRUCTURE_1lop| PDB=1lop | SCENE= }} |
| - | + | ||
| - | + | ||
| - | }} | + | |
'''CYCLOPHILIN A COMPLEXED WITH SUCCINYL-ALA-PRO-ALA-P-NITROANILIDE''' | '''CYCLOPHILIN A COMPLEXED WITH SUCCINYL-ALA-PRO-ALA-P-NITROANILIDE''' | ||
| Line 19: | Line 16: | ||
==About this Structure== | ==About this Structure== | ||
| - | 1LOP is a [[Single protein]] structure | + | 1LOP is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LOP OCA]. |
==Reference== | ==Reference== | ||
| Line 26: | Line 23: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Konno, M.]] | [[Category: Konno, M.]] | ||
| - | [[Category: | + | [[Category: Isomerase]] |
| - | [[Category: | + | [[Category: Rotamase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 00:07:27 2008'' | |
| - | + | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 21:07, 2 May 2008
CYCLOPHILIN A COMPLEXED WITH SUCCINYL-ALA-PRO-ALA-P-NITROANILIDE
Overview
The three-dimensional structure of Escherichia coli cytosolic cyclophilin A (CyPA) complexed with a tripeptide (succinyl-Ala-Pro-Ala-p-nitroanilide) was refined at 1.8 A resolution by the multiple isomorphous replacement method to a crystallographic R-factor of 17.6%. As in human CyPA, the peptide binding site in E. coli enzyme is in a cleft created on the surface of the upper sheet of two orthogonal beta-sheets. In this cleft, the walls of the hydrophobic pocket are formed by the side-chains of five non-polar residues, Phe48, Met49, Phe107, Leu108, and Try120, with Phe99 at the bottom. When the cis isomer of the tripeptide binds to the enzyme, a cis-proline ring is inserted into the hydrophobic pocket. Since the binding pocket of CyPAs are largely hydrophobic, the cis isomer of a peptide can be bound more firmly than the trans isomer. Distortion of the trans isomer could lead to better binding, but at an energetic cost of the distortion energy. At the periphery of the upper beta-sheet in E. coli CyPA, conformations of loops L1, L3, and L4 and the segment connecting alpha1 and beta3 with deletions or insertions against human CyPA differ significantly from those in human CyPA. The refined model also shows that steric hindrance to attachment of cyclosporin A (CsA) prevents E. coli CyPA forming a complex with CsA. Thus, the extra amino acid residue of E. coli CyPA, polar Gln89, lies along the pathway to the hydrophobic pocket of CyPA and seems to prevent the access hydrophobic part of CsA to the cleft of CyPA.
About this Structure
1LOP is a Single protein structure. Full crystallographic information is available from OCA.
Reference
The substrate-binding site in Escherichia coli cyclophilin A preferably recognizes a cis-proline isomer or a highly distorted form of the trans isomer., Konno M, Ito M, Hayano T, Takahashi N, J Mol Biol. 1996 Mar 15;256(5):897-908. PMID:8601841 Page seeded by OCA on Sat May 3 00:07:27 2008
