3g5i

<StructureSection load='3g5i' size='340' side='right' caption='[[3g5i]], [[Resolution|resolution]] 2.10&Aring;' scene=''>

<table><tr><td colspan='2'>[[3g5i]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Ecoli Ecoli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3G5I OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3G5I FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BME:BETA-MERCAPTOETHANOL'>BME</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=DNB:(2S,3S,4R,5R)-2-(3,4-DIAMINOPHENYL)-5-(HYDROXYMETHYL)PYRROLIDINE-3,4-DIOL'>DNB</scene></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=3g5i FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3g5i OCA], [http://pdbe.org/3g5i PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3g5i RCSB], [http://www.ebi.ac.uk/pdbsum/3g5i PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3g5i ProSAT]</span></td></tr>

== Function ==

[[http://www.uniprot.org/uniprot/RIHA_ECOLI RIHA_ECOLI]] Hydrolyzes with equal efficiency cytidine or uridine to ribose and cytosine or uracil, respectively.

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

Nucleoside hydrolases (NHs) are enzymes that catalyze the excision of the N-glycosidic bond in nucleosides to allow recycling of the nitrogenous bases. The fine details of the catalytic mechanism and the structural features imposing the substrate specificity of the various members of the NH family are still debated. Here we present the functional characterization of the Escherichia coli YbeK (RihA) protein as a pyrimidine nucleoside-preferring NH and its first crystal structure to 1.8 A resolution. The enzyme active site is occupied by either the alpha or beta anomer of ribose and provides the first structural description of the binding of the NH reaction product. While the amino acid residues involved in ribosyl binding are strictly conserved in pyrimidine-specific NHs, the residues involved in specific interactions with the nitrogenous bases differ considerably. Further comparison of the active site architecture of YbeK with the related NHs establishes structural determinants involved in triggering the conformational transition between the open and closed structures and suggests a mechanism for product release.

New insights into the mechanism of nucleoside hydrolases from the crystal structure of the Escherichia coli YbeK protein bound to the reaction product.,Muzzolini L, Versees W, Tornaghi P, Van Holsbeke E, Steyaert J, Degano M Biochemistry. 2006 Jan 24;45(3):773-82. PMID:16411753<ref>PMID:16411753</ref>

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

</div>

<div class="pdbe-citations 3g5i" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Ecoli]]

[[Category: Ribosylpyrimidine nucleosidase]]

[[Category: Degano, M]]

[[Category: Garau, G]]

[[Category: Muzzolini, L]]

[[Category: Tornaghi, P]]

[[Category: Hydrolase]]