1v2g
From Proteopedia
(New page: 200px<br /><applet load="1v2g" size="450" color="white" frame="true" align="right" spinBox="true" caption="1v2g, resolution 2.00Å" /> '''The L109P mutant of ...) |
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| - | [[Image:1v2g.jpg|left|200px]]<br /><applet load="1v2g" size=" | + | [[Image:1v2g.jpg|left|200px]]<br /><applet load="1v2g" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1v2g, resolution 2.00Å" /> | caption="1v2g, resolution 2.00Å" /> | ||
'''The L109P mutant of E. coli Thioesterase I/Protease I/Lysophospholipase L1 (TAP) in complexed with octanoic acid'''<br /> | '''The L109P mutant of E. coli Thioesterase I/Protease I/Lysophospholipase L1 (TAP) in complexed with octanoic acid'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Escherichia coli thioesterase I/protease I/lysophospholipase L(1) (TAP) is | + | Escherichia coli thioesterase I/protease I/lysophospholipase L(1) (TAP) is a multifunctional lysophospholipase and acyl-CoA thioesterase with a SGNH-hydrolase fold. The relationship between TAP's structure and its versatile substrate specificity, however, is unclear. Here, we present the crystal structure of TAP in complex with octanoic acid (TAP-OCA; OCA, a free fatty acid with eight carbon atoms, C(8)). A structural comparison of native TAP with TAP-OCA reveals a remarkable conformational change in loop(75)(-)(80), called "switch loop movement", upon OCA binding to the substrate-binding crevice of TAP. OCA binding to the substrate-binding crevice results in a continuous hydrophobic surface, which triggers switch loop movement. The switch loop movement is acyl chain length dependent, with an effect of stabilizing the Michaelis complex (MC) of TAP during catalysis, and is essential for TAP's substrate preference. The finding of a sulfate ion binding site in the TAP structures, together with previous enzyme kinetic analyses, leads us to postulate that a putative CoA binding site is essential for efficient catalysis of thioesters in TAP. We also present the crystal structure of L109P-OCA (TAP's L109P mutant in complex with OCA), in which Leu109 mutated to Pro109 abolishes switch loop movement. This result strengthens our hypothesis that the switch loop movement is induced by hydrophobic interactions. |
==About this Structure== | ==About this Structure== | ||
| - | 1V2G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with SO4, IMD and OCA as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1V2G is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=SO4:'>SO4</scene>, <scene name='pdbligand=IMD:'>IMD</scene> and <scene name='pdbligand=OCA:'>OCA</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1V2G OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Liaw, Y | + | [[Category: Liaw, Y C.]] |
| - | [[Category: Lin, S | + | [[Category: Lin, S C.]] |
| - | [[Category: Lo, Y | + | [[Category: Lo, Y C.]] |
[[Category: IMD]] | [[Category: IMD]] | ||
[[Category: OCA]] | [[Category: OCA]] | ||
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[[Category: sgnh-hydrolase fold]] | [[Category: sgnh-hydrolase fold]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:30:44 2008'' |
Revision as of 13:30, 21 February 2008
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The L109P mutant of E. coli Thioesterase I/Protease I/Lysophospholipase L1 (TAP) in complexed with octanoic acid
Overview
Escherichia coli thioesterase I/protease I/lysophospholipase L(1) (TAP) is a multifunctional lysophospholipase and acyl-CoA thioesterase with a SGNH-hydrolase fold. The relationship between TAP's structure and its versatile substrate specificity, however, is unclear. Here, we present the crystal structure of TAP in complex with octanoic acid (TAP-OCA; OCA, a free fatty acid with eight carbon atoms, C(8)). A structural comparison of native TAP with TAP-OCA reveals a remarkable conformational change in loop(75)(-)(80), called "switch loop movement", upon OCA binding to the substrate-binding crevice of TAP. OCA binding to the substrate-binding crevice results in a continuous hydrophobic surface, which triggers switch loop movement. The switch loop movement is acyl chain length dependent, with an effect of stabilizing the Michaelis complex (MC) of TAP during catalysis, and is essential for TAP's substrate preference. The finding of a sulfate ion binding site in the TAP structures, together with previous enzyme kinetic analyses, leads us to postulate that a putative CoA binding site is essential for efficient catalysis of thioesters in TAP. We also present the crystal structure of L109P-OCA (TAP's L109P mutant in complex with OCA), in which Leu109 mutated to Pro109 abolishes switch loop movement. This result strengthens our hypothesis that the switch loop movement is induced by hydrophobic interactions.
About this Structure
1V2G is a Single protein structure of sequence from Escherichia coli with , and as ligands. Full crystallographic information is available from OCA.
Reference
Substrate specificities of Escherichia coli thioesterase I/protease I/lysophospholipase L1 are governed by its switch loop movement., Lo YC, Lin SC, Shaw JF, Liaw YC, Biochemistry. 2005 Feb 15;44(6):1971-9. PMID:15697222
Page seeded by OCA on Thu Feb 21 15:30:44 2008
Categories: Escherichia coli | Single protein | Liaw, Y C. | Lin, S C. | Lo, Y C. | IMD | OCA | SO4 | Sgnh-hydrolase fold
