2pqe

Solution structure of proline-free mutant of staphylococcal nuclease

spinqualitylabelsall models 2pqe Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2pqe 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 NUC_STAAU Enzyme that catalyzes the hydrolysis of both DNA and RNA at the 5' position of the phosphodiester bond. 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 The role of cis-trans isomerizations of peptidyl-proline bonds in the enzyme activity of staphylococcal nuclease (SNase) was examined by mutation of proline residues. The proline-free SNase ([Pro-]SNase), namely, P11A/P31A/P42A/P47T/P56A/P117G-mutant SNase, was adopted for elucidating the correlation between the nuclease activity and the backbone conformational and dynamic states of SNase. The 3D solution structure of [Pro-]SNase has been determined by heteronuclear NMR experiments. Comparing the structure of [Pro-]SNase with the structure of SNase revealed the conformational differences between the two proteins. In the structure of [Pro-]SNase, conformational rearrangements were observed for the loop of residues Ala112-His121 containing a trans Lys116-Gly117 peptide bond and for the C-terminal alpha-helical loop of residues Leu137-Glu142. Mutation of proline at position 117 also caused the conformational rearrangement of the p-loop (Asp77-Leu89), which is remote from the Ala112-His121 loop. The Ala112-His121 loop and p-loop are placed closer to each other in [Pro-]SNase than in SNase. The backbone dynamic features of the omega-loop (Pro42-Pro56) of SNase are different from those of [Pro-]SNase. The backbone of the omega-loop exhibits restricted flexibility with slow conformational exchange motions in SNase, but is highly flexible in [Pro-]SNase. The analysis indicates that the restrained backbone conformation of the Ala112-His121 loop and restricted flexibility of the omega-loop are two dominant factors determining the enzyme activity of SNase. Of the two factors, the former is correlated with the strained cis Lys116-Pro117 peptide bond and the latter is correlated with the cis-trans isomerizations of the His46-Pro47 peptide bond. Restricted backbone conformational and motional flexibilities of loops containing peptidyl-proline bonds dominate the enzyme activity of staphylococcal nuclease.,Shan L, Tong Y, Xie T, Wang M, Wang J Biochemistry. 2007 Oct 16;46(41):11504-13. Epub 2007 Sep 22. PMID:17887731 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Staphylococcal nuclease 3D structures

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