2fxy

Solution structure of 55-72 segment of staphylococcal nucleaseSolution structure of 55-72 segment of staphylococcal nuclease

Structural highlights 2fxy is a 1 chain structure with sequence from Staphylococcus aureus. Full experimental information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Solution NMR Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function Q1WCB7_STAAU Publication Abstract from PubMed Two synthetic peptides, SNasealpha1 and SNasealpha2, corresponding to residues G55-I72 and K97-A109, respectively, of staphylococcal nuclease (SNase), are adopted for detecting the role of helix alpha1 (E57-A69) and helix alpha2 (M98-Q106) in the initiation of folding of SNase. The helix-forming tendencies of the two SNase peptide fragments are investigated using circular dichroism (CD) and two-dimensional (2D) nuclear magnetic resonance (NMR) methods in water and 40% trifluoroethanol (TFE) solutions. The coil-helix conformational transitions of the two peptides in the TFE-H2O mixture are different from each other. SNasealpha1 adopts a low population of localized helical conformation in water, and shows a gradual transition to helical conformation with increasing concentrations of TFE. SNasealpha2 is essentially unstructured in water, but undergoes a cooperative transition to a predominantly helical conformation at high TFE concentrations. Using the NMR data obtained in the presence of 40% TFE, an ensemble of alpha-helical structures has been calculated for both peptides in the absence of tertiary interactions. Analysis of all the experimental data available indicates that formation of ordered alpha-helical structures in the segments E57-A69 and M98-Q106 of SNase may require nonlocal interactions through transient contact with hydrophobic residues in other parts of the protein to stabilize the helical conformations in the folding. The folding of helix alpha1 is supposed to be effective in initiating protein folding. The formation of helix alpha2 depends strongly on the hydrophobic environment created in the protein folding, and is more important in the stabilization of the tertiary conformation of SNase. Two peptide fragments G55-I72 and K97-A109 from staphylococcal nuclease exhibit different behaviors in conformational preferences for helix formation.,Wang M, Shan L, Wang J Biopolymers. 2006 Oct 15;83(3):268-79. PMID:16767771 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

spinqualitylabelsall models 2fxy Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image