1lam: Difference between revisions
New page: left|200px<br /><applet load="1lam" size="450" color="white" frame="true" align="right" spinBox="true" caption="1lam, resolution 1.6Å" /> '''LEUCINE AMINOPEPTIDAS... |
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[[Image:1lam.jpg|left|200px]]<br /><applet load="1lam" size=" | [[Image:1lam.jpg|left|200px]]<br /><applet load="1lam" size="350" color="white" frame="true" align="right" spinBox="true" | ||
caption="1lam, resolution 1.6Å" /> | caption="1lam, resolution 1.6Å" /> | ||
'''LEUCINE AMINOPEPTIDASE (UNLIGATED)'''<br /> | '''LEUCINE AMINOPEPTIDASE (UNLIGATED)'''<br /> | ||
==Overview== | ==Overview== | ||
The three-dimensional structures of bovine lens leucine aminopeptidase | The three-dimensional structures of bovine lens leucine aminopeptidase (blLAP) complexed with L-leucinal and of the unliganded enzyme have been determined at crystallographic resolutions of 1.9 and 1.6 A, respectively. Leucinal binds as a hydrated gem-diol to the active site of b1LAP), resembling the presumed gem-diolated intermediate in the catalytic pathway. One hydroxyl group bridges the two active site metal ions, and the other OH group is coordinated to Zn1. The high-resolution structure of the unliganded enzyme reveals one metal-bound water ligand, which is bridging both zinc ions. Together, these structures support a mechanism in which the bridging water ligand is the attacking hydroxide ion nucleophile. The gem-diolate intermediate is probably stabilized by four coordinating bonds to the dizinc center and by interaction with Lys-262 and Arg-336. In the mechanism, Lys-262 polarizes the peptide carbonyl group, which is also coordinated to Zn1. The Arg-336 side chain interacts with the substrate and the gem-diolate intermediate via water molecules. Near Arg-336 in the b1LAP-leucinal structure, an unusually short hydrogen bond is found between two active site water molecules. | ||
==About this Structure== | ==About this Structure== | ||
1LAM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with ZN, CO3 and MRD as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Leucyl_aminopeptidase Leucyl aminopeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.11.1 3.4.11.1] Full crystallographic information is available from [http:// | 1LAM is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=ZN:'>ZN</scene>, <scene name='pdbligand=CO3:'>CO3</scene> and <scene name='pdbligand=MRD:'>MRD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Leucyl_aminopeptidase Leucyl aminopeptidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.11.1 3.4.11.1] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1LAM OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: Leucyl aminopeptidase]] | [[Category: Leucyl aminopeptidase]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Lipscomb, W | [[Category: Lipscomb, W N.]] | ||
[[Category: Straeter, N.]] | [[Category: Straeter, N.]] | ||
[[Category: CO3]] | [[Category: CO3]] | ||
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[[Category: metallopeptidase]] | [[Category: metallopeptidase]] | ||
''Page seeded by [http:// | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:43:13 2008'' | ||
Revision as of 14:43, 21 February 2008
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LEUCINE AMINOPEPTIDASE (UNLIGATED)
OverviewOverview
The three-dimensional structures of bovine lens leucine aminopeptidase (blLAP) complexed with L-leucinal and of the unliganded enzyme have been determined at crystallographic resolutions of 1.9 and 1.6 A, respectively. Leucinal binds as a hydrated gem-diol to the active site of b1LAP), resembling the presumed gem-diolated intermediate in the catalytic pathway. One hydroxyl group bridges the two active site metal ions, and the other OH group is coordinated to Zn1. The high-resolution structure of the unliganded enzyme reveals one metal-bound water ligand, which is bridging both zinc ions. Together, these structures support a mechanism in which the bridging water ligand is the attacking hydroxide ion nucleophile. The gem-diolate intermediate is probably stabilized by four coordinating bonds to the dizinc center and by interaction with Lys-262 and Arg-336. In the mechanism, Lys-262 polarizes the peptide carbonyl group, which is also coordinated to Zn1. The Arg-336 side chain interacts with the substrate and the gem-diolate intermediate via water molecules. Near Arg-336 in the b1LAP-leucinal structure, an unusually short hydrogen bond is found between two active site water molecules.
About this StructureAbout this Structure
1LAM is a Single protein structure of sequence from Bos taurus with , and as ligands. Active as Leucyl aminopeptidase, with EC number 3.4.11.1 Full crystallographic information is available from OCA.
ReferenceReference
Two-metal ion mechanism of bovine lens leucine aminopeptidase: active site solvent structure and binding mode of L-leucinal, a gem-diolate transition state analogue, by X-ray crystallography., Strater N, Lipscomb WN, Biochemistry. 1995 Nov 14;34(45):14792-800. PMID:7578088
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