5tim: Difference between revisions
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==REFINED 1.83 ANGSTROMS STRUCTURE OF TRYPANOSOMAL TRIOSEPHOSPHATE ISOMERASE, CRYSTALLIZED IN THE PRESENCE OF 2.4 M-AMMONIUM SULPHATE. A COMPARISON WITH THE STRUCTURE OF THE TRYPANOSOMAL TRIOSEPHOSPHATE ISOMERASE-GLYCEROL-3-PHOSPHATE COMPLEX== | |||
<StructureSection load='5tim' size='340' side='right' caption='[[5tim]], [[Resolution|resolution]] 1.83Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[5tim]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Trypanosoma_brucei_brucei Trypanosoma brucei brucei]. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=2tim 2tim]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5TIM OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5TIM FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=DTT:2,3-DIHYDROXY-1,4-DITHIOBUTANE'>DTT</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr> | |||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Triose-phosphate_isomerase Triose-phosphate isomerase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=5.3.1.1 5.3.1.1] </span></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5tim FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tim OCA], [http://www.rcsb.org/pdb/explore.do?structureId=5tim RCSB], [http://www.ebi.ac.uk/pdbsum/5tim 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/ti/5tim_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 == | |||
Triosephosphate isomerase (TIM) is a dimeric glycolytic enzyme. TIM from Trypanosoma brucei brucei has been crystallized at pH 7.0 in 2.4 M-ammonium sulphate. The well-diffracting crystals have one dimer per asymmetric unit. The structure has been refined at 1.83 A resolution with an R-factor of 18.3% for all data between 6 A and 1.83 A (37,568 reflections). The model consists of 3778 protein atoms and 297 solvent atoms. Subunit 1 is involved in considerably more crystal contacts than subunit 2. Correlated with these differences in crystal packing is the observation that only in the active site of subunit 2 is a sulphate ion bound. Furthermore, significant differences with respect to structure and flexibility are observed in three loops near the active site. In particular, there is a 7 A positional difference of the tip of the flexible loop (loop 6) when comparing subunit 1 and subunit 2. Also, the neighbouring loops (loop 5 and loop 7) have significantly different conformations and flexibility. In subunit 1, loop 6 is in an "open" conformation, in subunit 2, loop 6 is in an "almost closed" conformation. Only in the presence of a phosphate-containing ligand, such as glycerol-3-phosphate, does loop 6 take up the "closed" conformation. Loop 6 and loop 7 (and also to some extent loop 5) are rather flexible in the almost closed conformation, but well defined in the open and closed conformations. The closing of loop 6 (167 to 180), as observed in the almost closed conformation, slightly changes the main-chain conformation of the catalytic glutamate, Glu167, leading to a change of the chi 1 angle of this residue from approximately -60 degrees to approximately 60 degrees and the weakening of the hydrogen bonds between its polar side-chain atoms and Ser96. In the closed conformation, in the presence of glycerol-3-phosphate, the main-chain atoms of Glu167 remain in the same position as in the almost closed conformation, but the side-chain has rotated around the CA-CB bond changing chi 1 from approximately 60 degrees to approximately -60 degrees. In this new position the hydrogen bonding to Ser96 is completely lost and also a water-mediated salt bridge between OE2(Glu167) and NE(Arg99) is lost. Comparison of the two independently refined subunits, showed that the root-mean-square deviation for all 249 CA atoms is 0.9 A; for the CA atoms of the beta-strands this is only 0.2 A. The average B-factor for all subunit 1 and subunit 2 atoms is 20 A2 and 25 A2, respectively.(ABSTRACT TRUNCATED AT 400 WORDS) | |||
Refined 1.83 A structure of trypanosomal triosephosphate isomerase crystallized in the presence of 2.4 M-ammonium sulphate. A comparison with the structure of the trypanosomal triosephosphate isomerase-glycerol-3-phosphate complex.,Wierenga RK, Noble ME, Vriend G, Nauche S, Hol WG J Mol Biol. 1991 Aug 20;220(4):995-1015. PMID:1880808<ref>PMID:1880808</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Triose Phosphate Isomerase|Triose Phosphate Isomerase]] | *[[Triose Phosphate Isomerase|Triose Phosphate Isomerase]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Triose-phosphate isomerase]] | [[Category: Triose-phosphate isomerase]] | ||
[[Category: Trypanosoma brucei brucei]] | [[Category: Trypanosoma brucei brucei]] | ||
[[Category: Hol, W G.J | [[Category: Hol, W G.J]] | ||
[[Category: Wierenga, R K | [[Category: Wierenga, R K]] | ||