1cle
From Proteopedia
(New page: 200px<br /><applet load="1cle" size="450" color="white" frame="true" align="right" spinBox="true" caption="1cle, resolution 2.00Å" /> '''STRUCTURE OF UNCOMPL...) |
|||
| Line 1: | Line 1: | ||
| - | [[Image:1cle.gif|left|200px]]<br /><applet load="1cle" size=" | + | [[Image:1cle.gif|left|200px]]<br /><applet load="1cle" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1cle, resolution 2.00Å" /> | caption="1cle, resolution 2.00Å" /> | ||
'''STRUCTURE OF UNCOMPLEXED AND LINOLEATE-BOUND CANDIDA CYLINDRACEA CHOLESTEROL ESTERASE'''<br /> | '''STRUCTURE OF UNCOMPLEXED AND LINOLEATE-BOUND CANDIDA CYLINDRACEA CHOLESTEROL ESTERASE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | BACKGROUND: Candida cylindracea cholesterol esterase (CE) reversibly | + | BACKGROUND: Candida cylindracea cholesterol esterase (CE) reversibly hydrolyzes cholesteryl linoleate and oleate. CE belongs to the same alpha/beta hydrolase superfamily as triacylglycerol acyl hydrolases and cholinesterases. Other members of the family that have been studied by X-ray crystallography include Torpedo californica acetylcholinesterase, Geotrichum candidum lipase and Candida rugosa lipase. CE is homologous to C. rugosa lipase 1, a triacylglycerol acyl hydrolase, with which it shares 89% sequence identity. The present study explores the details of dimer formation of CE and the basis for its substrate specificity. RESULTS: The structures of uncomplexed and linoleate-bound CE determined at 1.9 A and 2.0 A resolution, respectively, reveal a dimeric association of monomers in which two active-site gorges face each other, shielding hydrophobic surfaces from the aqueous environment. The fatty-acid chain is buried in a deep hydrophobic pocket near the active site. The positioning of the cholesteryl moiety of the substrate is equivocal, but could be modeled in the hydrophobic core of the dimer interface. CONCLUSIONS: The monomer structure is the same in both the complexed and uncomplexed crystal forms. The dimers differ in the relative positions of the two monomers at the dimer interface. Of the 55 residues that are different in CE from those in C. rugosa lipase 1, 23 are located in the active site and at the dimer interface. The altered substrate specificity is a direct consequence of these substitutions. |
==About this Structure== | ==About this Structure== | ||
| - | 1CLE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Candida_cylindracea Candida cylindracea] with NAG, PO4 and CLL as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1CLE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Candida_cylindracea Candida cylindracea] with <scene name='pdbligand=NAG:'>NAG</scene>, <scene name='pdbligand=PO4:'>PO4</scene> and <scene name='pdbligand=CLL:'>CLL</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CLE OCA]. |
==Reference== | ==Reference== | ||
| Line 20: | Line 20: | ||
[[Category: substrate/product-bound]] | [[Category: substrate/product-bound]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:07:19 2008'' |
Revision as of 10:07, 21 February 2008
|
STRUCTURE OF UNCOMPLEXED AND LINOLEATE-BOUND CANDIDA CYLINDRACEA CHOLESTEROL ESTERASE
Overview
BACKGROUND: Candida cylindracea cholesterol esterase (CE) reversibly hydrolyzes cholesteryl linoleate and oleate. CE belongs to the same alpha/beta hydrolase superfamily as triacylglycerol acyl hydrolases and cholinesterases. Other members of the family that have been studied by X-ray crystallography include Torpedo californica acetylcholinesterase, Geotrichum candidum lipase and Candida rugosa lipase. CE is homologous to C. rugosa lipase 1, a triacylglycerol acyl hydrolase, with which it shares 89% sequence identity. The present study explores the details of dimer formation of CE and the basis for its substrate specificity. RESULTS: The structures of uncomplexed and linoleate-bound CE determined at 1.9 A and 2.0 A resolution, respectively, reveal a dimeric association of monomers in which two active-site gorges face each other, shielding hydrophobic surfaces from the aqueous environment. The fatty-acid chain is buried in a deep hydrophobic pocket near the active site. The positioning of the cholesteryl moiety of the substrate is equivocal, but could be modeled in the hydrophobic core of the dimer interface. CONCLUSIONS: The monomer structure is the same in both the complexed and uncomplexed crystal forms. The dimers differ in the relative positions of the two monomers at the dimer interface. Of the 55 residues that are different in CE from those in C. rugosa lipase 1, 23 are located in the active site and at the dimer interface. The altered substrate specificity is a direct consequence of these substitutions.
About this Structure
1CLE is a Single protein structure of sequence from Candida cylindracea with , and as ligands. Full crystallographic information is available from OCA.
Reference
Structure of uncomplexed and linoleate-bound Candida cylindracea cholesterol esterase., Ghosh D, Wawrzak Z, Pletnev VZ, Li N, Kaiser R, Pangborn W, Jornvall H, Erman M, Duax WL, Structure. 1995 Mar 15;3(3):279-88. PMID:7788294
Page seeded by OCA on Thu Feb 21 12:07:19 2008
Categories: Candida cylindracea | Single protein | Ghosh, D. | CLL | NAG | PO4 | Esterase | Substrate/product-bound
