5pal

<table><tr><td colspan='2'>[[5pal]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Leopard_shark Leopard shark]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5PAL OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=5PAL 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>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=5pal FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5pal OCA], [http://pdbe.org/5pal PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5pal RCSB], [http://www.ebi.ac.uk/pdbsum/5pal PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5pal ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/PRVA_TRISE PRVA_TRISE]] In muscle, parvalbumin is thought to be involved in relaxation after contraction. It binds two calcium ions.

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== Publication Abstract from PubMed ==

The three-dimensional structure of parvalbumin from leopard shark (Triakis semifasciata) with 109 amino acid residues (alpha-series) is described at 1.54 A resolution. Crystals were grown at 20 degrees C from 2.9 M-potassium/sodium phosphate solutions at pH 5.6. The space group is P3(1)21 and unit cell dimensions are a = b = 32.12 A and c = 149.0 A. The structure has been solved by the molecular replacement method using pike 4.10 parvalbumin as a model. The final structure refinement resulted in an R-factor of 17.3% for 11,363 independent reflections at 1.54 A resolution. The shark parvalbumin shows the main features of all parvalbumins: the folding of the chain including six alpha-helices, the salt bridge between Arg75 and Glu81, and the hydrophobic core. Compared to the structure of beta-parvalbumins from pike and carp, one main difference is observed: the chain is one residue longer and this additional residue, which extends the F helix, is involved through its C-terminal carboxylate group in a network of electrostatic contacts with two basic residues, His31 in the B helix and Lys36 in the BC segment. Furthermore, hydrogen bonds exist between the side-chains of Gln108 (F helix) and Tyr26 (B helix). There is therefore a "locking" of the tertiary structure through contacts between two sequentially distant regions in the protein and this is likely to contribute to making the stability of an alpha-parvalbumin higher in comparison to that of a beta-parvalbumin. The lengthening of the C-terminal F helix by one residue appears to be a major feature of alpha-parvalbumins in general, owing to the homologies of the amino acid sequences. Besides the lengthening of the C-terminal helix, the classification of the leopard shark parvalbumin in the alpha-series rests upon the observation of Lys13, Leu32, Glu61 and Val66. As this is the first crystal structure description of a parvalbumin from the alpha-phylogenetic lineage, it was hoped that it would clearly determine the presence or absence of a third cation binding site in parvalbumins belonging to the alpha-lineage. In beta-pike pI 4.10 parvalbumin, Asp61 participates as a direct ligand of a third site, the satellite of the CD site. In shark parvalbumin, as in nearly all alpha-parvalbumins, one finds Glu at position 61. Unfortunately, the conformation of the polar head of Glu61 cannot be inferred from the X-ray data.(ABSTRACT TRUNCATED AT 400 WORDS)

Crystal structure of the unique parvalbumin component from muscle of the leopard shark (Triakis semifasciata). The first X-ray study of an alpha-parvalbumin.,Roquet F, Declercq JP, Tinant B, Rambaud J, Parello J J Mol Biol. 1992 Feb 5;223(3):705-20. PMID:1542115<ref>PMID:1542115</ref>

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

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<div class="pdbe-citations 5pal" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Leopard shark]]

[[Category: Declercq, J P]]

[[Category: Parello, J]]

[[Category: Rambaud, J]]

[[Category: Roquet, F]]

[[Category: Tinant, B]]

[[Category: Calcium-binding protein]]