4hst

<StructureSection load='4hst' size='340' side='right' caption='[[4hst]], [[Resolution|resolution]] 1.57&Aring;' scene=''>

<table><tr><td colspan='2'>[[4hst]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"chlorobacterium"_guillebeau_1890,_nom._rejic._opin._6_(not_"chlorobacterium"_lauterborn_1916) "chlorobacterium" guillebeau 1890, nom. rejic. opin. 6 (not "chlorobacterium" lauterborn 1916)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HST OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4HST FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GLJ:5,5-DIHYDROXY-L-NORVALINE'>GLJ</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4hsr|4hsr]]</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=4hst FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hst OCA], [http://pdbe.org/4hst PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4hst RCSB], [http://www.ebi.ac.uk/pdbsum/4hst PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4hst ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

The crystal structure of wild-type form of glutaryl-7-ACA acylase from Pseudomonas N176 and a double mutant of the protein (His57betaSer/His70betaSer) that displays enhanced catalytic efficiency on cephalosporin C over glutaryl-7-aminocephalosporanic acid has been determined. The structures show a heterodimer made up of an alpha chain (229 residues) and a beta chain (543 residues) with a deep cavity, which constitutes the active site. Comparison of the wild-type and mutant structures provide insights into the molecular reasons for the observed enhanced specificity on cephalosporin C over glutaryl-7-aminocephalosporanic acid and offered the basis to evolve a further improve enzyme variant. The nucleophilic catalytic serine residue, Ser1beta, is situated at the base of the active site cavity. The electron density reveals a ligand covalently bound to the catalytic serine residue such that a tetrahedral adduct is formed. This is proposed to mimic the transition state of the enzyme for both the maturation step and the catalysis of the substrates. A view of the transitions state configuration of the enzyme provides important insights into the mechanism of substrate binding and catalysis.

 

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== References ==

[[Category: Anandan, A]]

[[Category: Flematti, G]]

[[Category: Golden, E]]

[[Category: Molla, G]]

[[Category: Patterson, R]]

[[Category: Pollegioni, L]]

[[Category: Rosini, E]]

[[Category: Tie, W J]]

[[Category: Vrielink, A]]

[[Category: Transition state analogue]]