1mff: Difference between revisions
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< | ==MACROPHAGE MIGRATION INHIBITORY FACTOR Y95F MUTANT== | ||
<StructureSection load='1mff' size='340' side='right'caption='[[1mff]], [[Resolution|resolution]] 2.00Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[1mff]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MFF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1MFF FirstGlance]. <br> | |||
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2Å</td></tr> | |||
-- | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1mff FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1mff OCA], [https://pdbe.org/1mff PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1mff RCSB], [https://www.ebi.ac.uk/pdbsum/1mff PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1mff ProSAT]</span></td></tr> | ||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/MIF_MOUSE MIF_MOUSE] Pro-inflammatory cytokine. Involved in the innate immune response to bacterial pathogens. The expression of MIF at sites of inflammation suggests a role as mediator in regulating the function of macrophages in host defense. Counteracts the anti-inflammatory activity of glucocorticoids. Has phenylpyruvate tautomerase and dopachrome tautomerase activity (in vitro), but the physiological substrate is not known. It is not clear whether the tautomerase activity has any physiological relevance, and whether it is important for cytokine activity (By similarity). | |||
== 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/mf/1mff_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/main_output.php?pdb_ID=1mff ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Phenylpyruvate tautomerase (PPT) has been studied periodically since its activity was first described over forty years ago. In the last two years, the mechanism of PPT has been investigated more extensively because of the discovery that PPT is the same protein as the immunoregulatory cytokine known as macrophage migration inhibitory factor (MIF). The mechanism of PPT is likely to involve general base-general acid catalysis. While several lines of evidence implicate Pro-1 as the general base, the identity of the general acid remains unknown. Crystal structures of MIF with the competitive inhibitor (E)-2-fluoro-p-hydroxycinnamate bound in the active site and that of the protein complexed with the enol form of a substrate, (p-hydroxyphenyl)pyruvate, suggest that Tyr-95 is the only candidate in the vicinity that can function as a general acid catalyst. Although Tyr-95 is nearby the bound inhibitor and substrate, it is not within hydrogen bonding distance of either ligand. In this study, Tyr-95 was mutated to phenylalanine, and the kinetic and structural properties of the Y95F mutant were determined. This alteration produces a fully active enzyme, which shows no significant structural changes in the active site. The results indicate that Tyr-95 does not function as the general acid catalyst in the reaction catalyzed by wild-type PPT. The mechanism of PPT was studied further by constructing and characterizing the kinetic properties of two mutants of Pro-1 (P1G and P1A) and one mutant of Asn-97 (N97A). The mutation of Asn-97, a residue implicated in the binding of the phenolic hydroxy group of the keto and enol isomers of (p-hydroxyphenyl)pyruvate and of (E)-2-fluoro-p-hydroxycinnamate affects only the binding affinity of the inhibitor. However, the mutations of Pro-1 have a profound effect on the values of k(cat) and k(cat)/K(m) and clearly show that Pro-1 is a critical residue in the reaction. The results are discussed in terms of a mechanism in which Pro-1 functions as both the general acid and the general base catalyst. | |||
Mechanism of the phenylpyruvate tautomerase activity of macrophage migration inhibitory factor: properties of the P1G, P1A, Y95F, and N97A mutants.,Stamps SL, Taylor AB, Wang SC, Hackert ML, Whitman CP Biochemistry. 2000 Aug 15;39(32):9671-8. PMID:10933783<ref>PMID:10933783</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1mff" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Macrophage inhibitory factor 3D structures|Macrophage inhibitory factor 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
== | |||
< | |||
[[Category: Mus musculus]] | [[Category: Mus musculus]] | ||
[[Category: Hackert | [[Category: Hackert ML]] | ||
[[Category: Stamps | [[Category: Stamps SL]] | ||
[[Category: Taylor | [[Category: Taylor AB]] | ||
[[Category: Wang | [[Category: Wang SC]] | ||
[[Category: Whitman | [[Category: Whitman CP]] | ||