3thi

<StructureSection load='3thi' size='340' side='right' caption='[[3thi]], [[Resolution|resolution]] 2.00&Aring;' scene=''>

<table><tr><td colspan='2'>[[3thi]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"vibrio_subtilis"_ehrenberg_1835 "vibrio subtilis" ehrenberg 1835]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3THI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3THI FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><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/Thiamine_pyridinylase Thiamine pyridinylase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.2 2.5.1.2] </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=3thi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3thi OCA], [http://pdbe.org/3thi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3thi RCSB], [http://www.ebi.ac.uk/pdbsum/3thi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3thi ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/THI1_PANTH THI1_PANTH]] Degrades thiamine by replacing its thiazole moiety with a wide range of nucleophiles.

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== Publication Abstract from PubMed ==

Thiaminase-I catalyzes the replacement of the thiazole moiety of thiamin with a wide variety of nucleophiles, such as pyridine, aniline, catechols, quinoline, and cysteine. The crystal structure of the enzyme from Bacillus thiaminolyticus was determined at 2.5 A resolution by multiple isomorphous replacement and refined to an R factor of 0.195 (Rfree = 0.272). Two other structures, one native and one containing a covalently bound inhibitor, were determined at 2.0 A resolution by molecular replacement from a second crystal form and were refined to R factors of 0.205 and 0.217 (Rfree = 0.255 and 0.263), respectively. The overall structure contains two alpha/beta-type domains separated by a large cleft. At the base of the cleft lies Cys113, previously identified as a key active site nucleophile. The structure with a covalently bound thiamin analogue, which functions as a mechanism-based inactivating agent, confirms the location of the active site. Glu241 appears to function as an active site base to increase the nucleophilicity of Cys113. The mutant Glu241Gln was made and shows no activity. Thiaminase-I shows no sequence identity to other proteins in the sequence databases, but the three-dimensional structure shows very high structural homology to the periplasmic binding proteins and the transferrins.

Crystal structure of thiaminase-I from Bacillus thiaminolyticus at 2.0 A resolution.,Campobasso N, Costello CA, Kinsland C, Begley TP, Ealick SE Biochemistry. 1998 Nov 10;37(45):15981-9. PMID:9843405<ref>PMID:9843405</ref>

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

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== References ==

<references/>

[[Category: Vibrio subtilis ehrenberg 1835]]

[[Category: Thiamine pyridinylase]]

[[Category: Begley, T P]]

[[Category: Campobasso, N]]

[[Category: Ealick, S E]]

[[Category: Transferase]]