2scp

<table><tr><td colspan='2'>[[2scp]] is a 2 chain structure. This structure supersedes the now removed PDB entry [http://oca.weizmann.ac.il/oca-bin/send-pdb?obs=1&id=1scp 1scp]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2SCP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2SCP FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>

[[https://www.uniprot.org/uniprot/SCP_HEDDI SCP_HEDDI]] Like parvalbumins, SCP's seem to be more abundant in fast contracting muscles, but no functional relationship can be established from this distribution.

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== Publication Abstract from PubMed ==

The crystal structure of a sarcoplasmic Ca(2+)-binding protein (SCP) from the sandworm Nereis diversicolor has been determined and refined at 2.0 A resolution using restrained least-squares techniques. The two molecules in the crystallographic asymmetric unit, which are related by a non-crystallographic 2-fold axis, were refined independently. The refined model includes all 174 residues and three calcium ions for each molecule, as well as 213 water molecules. The root-mean-square difference in co-ordinates for backbone atoms and calcium ions of the two molecules is 0.51 A. The final crystallographic R-factor, based on 18,959 reflections in the range 2.0 A less than or equal to d less than or equal to 7.0 A, with intensities exceeding 2.0 sigma, is 0.182. Bond lengths and bond angles in the molecules have root-mean-square deviations from ideal values of 0.013 A and 2.2 degrees, respectively. SCP has four distinct domains with the typical helix-loop-helix (EF-hand) Ca(2+)-binding motif, although the second Ca(2+)-binding domain is not functional due to amino acid changes in the loop. The structure shows several unique features compared to other Ca(2+)-binding proteins with four EF-hand domains. The overall structure is highly compact and globular with a predominant hydrophobic core, unlike the extended dumbbell-shaped structure of calmodulin or troponin C. A hydrophobic tail at the COOH terminus adds to the structural stability by packing against a hydrophobic pocket created by the folding of the NH2 and COOH-terminal Ca(2+)-binding domain pairs. The first and second domains show different helix-packing arrangements from any previously described for Ca(2+)-binding proteins.

Structure of a sarcoplasmic calcium-binding protein from Nereis diversicolor refined at 2.0 A resolution.,Vijay-Kumar S, Cook WJ J Mol Biol. 1992 Mar 20;224(2):413-26. PMID:1560459<ref>PMID:1560459</ref>

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

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== References ==

<references/>

[[Category: Cook, W J]]

[[Category: Vijay-Kumar, S]]

[[Category: Binding protein]]