1s3p

Crystal structure of rat alpha-parvalbumin S55D/E59D mutantCrystal structure of rat alpha-parvalbumin S55D/E59D mutant

Structural highlights 1s3p is a 1 chain structure with sequence from Buffalo rat. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: , Related: 1rwy Gene: PVALB, PVA (Buffalo rat) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [PRVA_RAT] In muscle, parvalbumin is thought to be involved in relaxation after contraction. It binds two calcium ions. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed In model peptide systems, Ca2+ affinity is maximized in EF-hand motifs containing four carboxylates positioned on the +x and -x and +z and -z axes; introduction of a fifth carboxylate ligand reduces the affinity. However, in rat beta-parvalbumin, replacement of Ser-55 with aspartate heightens divalent ion affinity [Henzl, M. T., et al. (1996) Biochemistry 35, 5856-5869]. The corresponding alpha-parvalbumin variant (S55D/E59D) likewise exhibits elevated affinity [Henzl, M. T., et al. (2003) Anal. Biochem. 319, 216-233]. To determine whether these mutations produce a variation on the archetypal EF-hand coordination scheme, we have obtained high-resolution X-ray crystallographic data for alpha S55D/E59D. As anticipated, the aspartyl carboxylate replaces the serine hydroxyl at the +z coordination position. Interestingly, the Asp-59 carboxylate abandons the role it plays as an outer sphere ligand in wild-type rat beta, rotating away from the Ca2+ and, instead, forming a hydrogen bond with the amide of Glu-62. Superficially, the coordination sphere in the CD site of alpha S55D/E59D resembles that in the EF site. However, the orientation of the Asp-59 side chain is predicted to stabilize the D-helix, which may contribute to the heightened divalent ion affinity. DSC data indicate that the alpha S55D/E59D variant retains the capacity to bind 1 equiv of Na+. Consistent with this finding, when binding measurements are conducted in K(+)-containing buffer, divalent ion affinity is markedly higher. In 0.15 M KCl and 0.025 M Hepes-KOH (pH 7.4) at 5 degrees C, the macroscopic Ca2+ binding constants are 1.8 x 10(10) and 2.0 x 10(9) M(-1). The corresponding Mg2+ binding constants are 2.7 x 10(6) and 1.2 x 10(5) M(-1). Crystal structure of a high-affinity variant of rat alpha-parvalbumin.,Lee YH, Tanner JJ, Larson JD, Henzl MT Biochemistry. 2004 Aug 10;43(31):10008-17. PMID:15287728 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 1s3p, resolution 2.00Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image