5tim

<table><tr><td colspan='2'>[[5tim]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Trybb Trybb]. 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://proteopedia.org/fgij/fg.htm?mol=5TIM FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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://proteopedia.org/fgij/fg.htm?mol=5tim FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5tim OCA], [http://pdbe.org/5tim PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5tim RCSB], [http://www.ebi.ac.uk/pdbsum/5tim PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5tim ProSAT]</span></td></tr>

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== 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&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 5tim" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Triose-phosphate isomerase]]

[[Category: Trybb]]

[[Category: Hol, W G.J]]

[[Category: Wierenga, R K]]