2PQE

Solution structure of proline-free mutant of staphylococcal nuclease

2PQE の概要

• エントリーDOI: 10.2210/pdb2pqe/pdb
• NMR情報: BMRB: 15232
• 分子名称: Thermonuclease (1 entity in total)
• 機能のキーワード: beta barrel, ob fold, hydrolase
• 由来する生物種: Staphylococcus aureus
• 細胞内の位置: Secreted (By similarity): Q8NXI6
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 16678.12

構造登録者

Shan, L.,Tong, Y.,Xie, T.,Wang, M.,Wang, J. (登録日: 2007-05-01, 公開日: 2007-06-19, 最終更新日: 2024-05-22)

主引用文献

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

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: 17887731
DOI: 10.1021/bi7009794

実験手法

SOLUTION NMR