View source for 4qef


==Human Carbonic Anhydrase II V207I - cyanate inhibitor complex==
<StructureSection load='4qef' size='340' side='right' caption='[[4qef]], [[Resolution|resolution]] 1.47&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4qef]] is a 1 chain structure. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=4gge 4gge]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4QEF OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4QEF FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=0NM:CYANIC+ACID'>0NM</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[2ili|2ili]], [[4e5q|4e5q]]</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Carbonate_dehydratase Carbonate dehydratase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.2.1.1 4.2.1.1] </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=4qef FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4qef OCA], [http://pdbe.org/4qef PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4qef RCSB], [http://www.ebi.ac.uk/pdbsum/4qef PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4qef ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/CAH2_HUMAN CAH2_HUMAN]] Defects in CA2 are the cause of osteopetrosis autosomal recessive type 3 (OPTB3) [MIM:[http://omim.org/entry/259730 259730]]; also known as osteopetrosis with renal tubular acidosis, carbonic anhydrase II deficiency syndrome, Guibaud-Vainsel syndrome or marble brain disease. Osteopetrosis is a rare genetic disease characterized by abnormally dense bone, due to defective resorption of immature bone. The disorder occurs in two forms: a severe autosomal recessive form occurring in utero, infancy, or childhood, and a benign autosomal dominant form occurring in adolescence or adulthood. Autosomal recessive osteopetrosis is usually associated with normal or elevated amount of non-functional osteoclasts. OPTB3 is associated with renal tubular acidosis, cerebral calcification (marble brain disease) and in some cases with mental retardation.<ref>PMID:1928091</ref> <ref>PMID:1542674</ref> <ref>PMID:8834238</ref> <ref>PMID:9143915</ref> <ref>PMID:15300855</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/CAH2_HUMAN CAH2_HUMAN]] Essential for bone resorption and osteoclast differentiation (By similarity). Reversible hydration of carbon dioxide. Can hydrate cyanamide to urea. Involved in the regulation of fluid secretion into the anterior chamber of the eye.<ref>PMID:10550681</ref> <ref>PMID:11831900</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The binding of anions to carbonic anhydrase II (CA II) has been attributed to high affinity for the active-site zinc. An anion of interest is cyanate, for which contrasting binding modes have been reported in the literature. Previous spectroscopic data have shown cyanate behaving as an inhibitor, directly binding to the zinc, in contrast to previous crystallographic data that implied that cyanate acts as a substrate mimic that is not directly bound to the zinc but overlaps with the binding site of the substrate CO2. Wild-type and the V207I variant of CA II have been expressed and X-ray crystal structures of their cyanate complexes have been determined to 1.7 and 1.5 A resolution, respectively. The rationale for the V207I CA II variant was its close proximity to the CO2-binding site. Both structures clearly show that the cyanate binds directly to the zinc. In addition, inhibition constants ( approximately 40 microM) were measured using (18)O-exchange mass spectrometry for wild-type and V207I CA II and were similar to those determined previously (Supuran et al., 1997). Hence, it is concluded that under the conditions of these experiments the binding of cyanate to CA II is directly to the zinc, displacing the zinc-bound solvent molecule, and not in a site that overlaps with the CO2 substrate-binding site.

Human carbonic anhydrase II-cyanate inhibitor complex: putting the debate to rest.,West D, Pinard MA, Tu C, Silverman DN, McKenna R Acta Crystallogr F Struct Biol Commun. 2014 Oct 1;70(Pt 10):1324-7. doi:, 10.1107/S2053230X14018135. Epub 2014 Sep 25. PMID:25286933<ref>PMID:25286933</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4qef" style="background-color:#fffaf0;"></div>

==See Also==
*[[Carbonic anhydrase|Carbonic anhydrase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Carbonate dehydratase]]
[[Category: West, D M]]
[[Category: Lyase]]
[[Category: Lyase-lyase inhibitor complex]]
[[Category: Proton transfer]]