2PQE
Solution structure of proline-free mutant of staphylococcal nuclease
Summary for 2PQE
| Entry DOI | 10.2210/pdb2pqe/pdb |
| NMR Information | BMRB: 15232 |
| Descriptor | Thermonuclease (1 entity in total) |
| Functional Keywords | beta barrel, ob fold, hydrolase |
| Biological source | Staphylococcus aureus |
| Cellular location | Secreted (By similarity): Q8NXI6 |
| Total number of polymer chains | 1 |
| Total formula weight | 16678.12 |
| Authors | |
| Primary citation | Shan, L.,Tong, Y.,Xie, T.,Wang, M.,Wang, J. Restricted backbone conformational and motional flexibilities of loops containing peptidyl-proline bonds dominate the enzyme activity of staphylococcal nuclease. Biochemistry, 46:11504-11513, 2007 Cited by PubMed Abstract: 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. PubMed: 17887731DOI: 10.1021/bi7009794 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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