1mku: Difference between revisions
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[[Image: | ==CARBOXYLIC ESTER HYDROLASE, ORTHORHOMBIC FORM OF THE TRIPLE MUTANT== | ||
<StructureSection load='1mku' size='340' side='right' caption='[[1mku]], [[Resolution|resolution]] 1.80Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1mku]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MKU OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1MKU FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">PRO-PLA2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9913 Bos taurus])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Phospholipase_A(2) Phospholipase A(2)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.1.1.4 3.1.1.4] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1mku FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mku OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1mku RCSB], [http://www.ebi.ac.uk/pdbsum/1mku PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/mk/1mku_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
The aspartate-99 of secreted phospholipase A2 (PLA2) has been proposed to be critical for the catalytic mechanism and interfacial activation of PLA2. Aspartate-99 connects the catalytic machinery (including the catalytic diad, the putative catalytic waters W5 and W6, and the calcium cofactor) to the hydrogen-bonding network. The latter involves Y52, Y73, the structural water, and the N-terminal region putatively required for the interfacial activation. A triple mutant of bovine pancreatic PLA2 with substitutions aspartate plus adjacent tyrosine residues (Y52,73F/D99N) was constructed, its X-ray structure was determined, and kinetic characteristics were analyzed. The kinetic properties of the D99N mutant constructed previously were also further analyzed. The X-ray structure of the Y52,73F/D99N mutant indicated a substantial disruption of the hydrogen-bonding network including the loss of the structural water similar to that seen in the structure of the D99N mutant published previously [Kumar, A., Sekharudu, Y. C., Ramakrishnan, B., Dupureur, C. M., Zhu, H., Tsai, M.-D., & Sundaralingam, M. (1994) Protein Sci. 3, 2082-2088]. Kinetic analysis demonstrated that these mutants possessed considerable catalytic activity with a k(cat) value of about 5% compared to WT. The values of the interfacial Michaelis constant were also little perturbed (ca. 4-fold lower for D99N and marginally higher for Y52,73F/D99N). The results taken together suggest that the hydrogen-bonding network is not critically important for interfacial activation. Instead, it is the chemical step that is perturbed, though only modestly, in the mutants. | |||
Phospholipase A2 engineering. Structural and functional roles of the highly conserved active site residue aspartate-99.,Sekar K, Yu BZ, Rogers J, Lutton J, Liu X, Chen X, Tsai MD, Jain MK, Sundaralingam M Biochemistry. 1997 Mar 18;36(11):3104-14. PMID:9115986<ref>PMID:9115986</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Phospholipase A2|Phospholipase A2]] | *[[Phospholipase A2|Phospholipase A2]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Sundaralingam, M.]] | [[Category: Sundaralingam, M.]] | ||
Revision as of 18:41, 28 September 2014
CARBOXYLIC ESTER HYDROLASE, ORTHORHOMBIC FORM OF THE TRIPLE MUTANTCARBOXYLIC ESTER HYDROLASE, ORTHORHOMBIC FORM OF THE TRIPLE MUTANT
Structural highlights
Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe aspartate-99 of secreted phospholipase A2 (PLA2) has been proposed to be critical for the catalytic mechanism and interfacial activation of PLA2. Aspartate-99 connects the catalytic machinery (including the catalytic diad, the putative catalytic waters W5 and W6, and the calcium cofactor) to the hydrogen-bonding network. The latter involves Y52, Y73, the structural water, and the N-terminal region putatively required for the interfacial activation. A triple mutant of bovine pancreatic PLA2 with substitutions aspartate plus adjacent tyrosine residues (Y52,73F/D99N) was constructed, its X-ray structure was determined, and kinetic characteristics were analyzed. The kinetic properties of the D99N mutant constructed previously were also further analyzed. The X-ray structure of the Y52,73F/D99N mutant indicated a substantial disruption of the hydrogen-bonding network including the loss of the structural water similar to that seen in the structure of the D99N mutant published previously [Kumar, A., Sekharudu, Y. C., Ramakrishnan, B., Dupureur, C. M., Zhu, H., Tsai, M.-D., & Sundaralingam, M. (1994) Protein Sci. 3, 2082-2088]. Kinetic analysis demonstrated that these mutants possessed considerable catalytic activity with a k(cat) value of about 5% compared to WT. The values of the interfacial Michaelis constant were also little perturbed (ca. 4-fold lower for D99N and marginally higher for Y52,73F/D99N). The results taken together suggest that the hydrogen-bonding network is not critically important for interfacial activation. Instead, it is the chemical step that is perturbed, though only modestly, in the mutants. Phospholipase A2 engineering. Structural and functional roles of the highly conserved active site residue aspartate-99.,Sekar K, Yu BZ, Rogers J, Lutton J, Liu X, Chen X, Tsai MD, Jain MK, Sundaralingam M Biochemistry. 1997 Mar 18;36(11):3104-14. PMID:9115986[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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