View source for 4mzz


==Crystal structure of Bovine 3 Glu-Osteocalcin.==
<StructureSection load='4mzz' size='340' side='right'caption='[[4mzz]], [[Resolution|resolution]] 1.88&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4mzz]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MZZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4MZZ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.88&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4mzz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mzz OCA], [https://pdbe.org/4mzz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4mzz RCSB], [https://www.ebi.ac.uk/pdbsum/4mzz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4mzz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/OSTCN_BOVIN OSTCN_BOVIN] Constitutes 1-2% of the total bone protein. It binds strongly to apatite and calcium.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The 3 Glu form of osteocalcin (3 Glu-OCN) is increased in serum during low vitamin K intake or oral anticoagulant use (warfarin). Previous reports using circular dichroism show it is less structured than 3 Gla Ca(2)(+)-osteocalcin and does not bind strongly to bone mineral. Recent studies have suggested a role for 3 Glu-OCN as a potential regulator of glucose metabolism. A G-protein-coupled receptor, GPRC6a, found in the pancreas and testes was identified as the putative osteocalcin receptor. The purpose of this study is to determine the high-resolution structure of bovine 3 Glu-OCN, using X-ray crystallography, to understand molecular interactions with mineral and the GPRC6a receptor. Diffraction quality crystals of thermally decarboxylated bovine osteocalcin were grown, and the crystal structure was determined to 1.88 A resolution. The final refined structure contained residues 17-47 and, like 3 Gla Ca(2)(+)-OCN, consisted of three alpha-helices surrounding a hydrophobic core, a C23-C29 disulfide bond between two of the helices, and no bound Ca(2)(+). Thus, the helical structure of 3 Glu-OCN is Ca(2)(+)-independent but similar to that of 3 Gla Ca(2)(+)-OCN. A reduced level of mineral binding could result from a lower number of Ca(2)(+) coordinating ligands on 3 Glu-OCN. The structure suggests the GPRC6a receptor may respond to helical osteocalcin and will aid in providing molecular mechanistic insight into the role of 3 Glu-OCN in glucose homeostasis.

X-ray crystal structure of bovine 3 Glu-osteocalcin.,Malashkevich VN, Almo SC, Dowd TL Biochemistry. 2013 Nov 26;52(47):8387-92. doi: 10.1021/bi4010254. Epub 2013 Nov, 12. PMID:24138653<ref>PMID:24138653</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4mzz" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bos taurus]]
[[Category: Large Structures]]
[[Category: Almo SC]]
[[Category: Dowd TL]]
[[Category: Malashkevich VN]]