1trb: Difference between revisions

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[[Image:1trb.gif|left|200px]]<br /><applet load="1trb" size="350" color="white" frame="true" align="right" spinBox="true"
caption="1trb, resolution 2.0&Aring;" />
'''CONVERGENT EVOLUTION OF SIMILAR FUNCTION IN TWO STRUCTURALLY DIVERGENT ENZYMES'''<br />


==Overview==
==CONVERGENT EVOLUTION OF SIMILAR FUNCTION IN TWO STRUCTURALLY DIVERGENT ENZYMES==
An example of two related enzymes that catalyse similar reactions but possess different active sites is provided by comparing the structure of Escherichia coli thioredoxin reductase with glutathione reductase. Both are dimeric enzymes that catalyse the reduction of disulphides by pyridine nucleotides through an enzyme disulphide and a flavin. Human glutathione reductase contains four structural domains within each molecule: the flavin-adenine dinucleotide (FAD)- and nicotinamide-adenine dinucleotide phosphate (NADPH)-binding domains, the 'central' domain and the C-terminal domain that provides the dimer interface and part of the active site. Although both enzymes share the same catalytic mechanism and similar tertiary structures, their active sites do not resemble each other. We have determined the crystal structure of E. coli thioredoxin reductase at 2 A resolution, and show that thioredoxin reductase lacks the domain that provides the dimer interface in glutathione reductase, and forms a completely different dimeric structure. The catalytically active disulphides are located in different domains on opposite sides of the flavin ring system. This suggests that these enzymes diverged from an ancestral nucleotide-binding protein and acquired their disulphide reductase activities independently.
<StructureSection load='1trb' size='340' side='right'caption='[[1trb]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1trb]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TRB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1TRB 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]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene></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=1trb FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1trb OCA], [https://pdbe.org/1trb PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1trb RCSB], [https://www.ebi.ac.uk/pdbsum/1trb PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1trb ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRXB_ECOLI TRXB_ECOLI]
== 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/tr/1trb_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=1trb ConSurf].
<div style="clear:both"></div>


==About this Structure==
==See Also==
1TRB 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=FAD:'>FAD</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Thioredoxin-disulfide_reductase Thioredoxin-disulfide reductase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.8.1.9 1.8.1.9] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TRB OCA].
*[[Thioredoxin reductase 3D structures|Thioredoxin reductase 3D structures]]
 
__TOC__
==Reference==
</StructureSection>
Convergent evolution of similar function in two structurally divergent enzymes., Kuriyan J, Krishna TS, Wong L, Guenther B, Pahler A, Williams CH Jr, Model P, Nature. 1991 Jul 11;352(6331):172-4. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=2067578 2067578]
[[Category: Escherichia coli]]
[[Category: Escherichia coli]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Thioredoxin-disulfide reductase]]
[[Category: Krishna TSR]]
[[Category: Krishna, T S.R.]]
[[Category: Kuriyan J]]
[[Category: Kuriyan, J.]]
[[Category: FAD]]
[[Category: oxidoreductase(flavoenzyme)]]
 
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