1RKN

Solution structure of 1-110 fragment of Staphylococcal Nuclease with G88W mutation

Summary for 1RKN

• Entry DOI: 10.2210/pdb1rkn/pdb
• NMR Information: BMRB: 5536
• Descriptor: Thermonuclease (1 entity in total)
• Functional Keywords: staphylococcal nuclease, folding, g88w110, hydrolase
• Biological source: Staphylococcus aureus
• Cellular location: Nuclease A: Secreted. Nuclease B: Membrane: P00644
• Total number of polymer chains: 1
• Total formula weight: 12454.56

Authors

Liu, D.S.,Feng, Y.G.,Ye, K.Q.,Shan, L.,Wang, J.F. (deposition date: 2003-11-22, release date: 2004-12-07, Last modification date: 2024-05-29)

Primary citation

Xie, T.,Liu, D.,Feng, Y.,Shan, L.,Wang, J.F.
Folding stability and cooperativity of the three forms of 1-110 residues fragment of staphylococcal nuclease
Biophys.J., 92:2090-2107, 2007

PubMed Abstract: Folding stability and cooperativity of the three forms of 1-110 residues fragment of staphylococcal nuclease (SNase110) have been studied by various biophysical and NMR methods. Samples of G-88W- and V-66W-mutant SNase110, namely G-88W110 and V-66W110, in aqueous solution and SNase110 in 2.0 M TMAO are adopted in this study. The unfolding transitions and folded conformations of the three SNase fragments were detected by far- and near-ultraviolet circular dichroism and intrinsic tryptophan fluorescence measurements. The tertiary structures and internal motions of the fragments were determined by NMR spectroscopy. Both G-88W and V-66W single mutations as well as a small organic osmolyte (Trimethylamine N-oxide, TMAO) can fold the fragment into a native-like conformation. However, the tertiary structures of the three fragments exhibit different degrees of folding stability and compactness. G-88W110 adopts a relatively rigid structure representing a most stable native-like beta-subdomain conformation of the three fragments. V-66W110- and TMAO-stabilized SNase110 produce less compact structures having a less stable "beta-barrel" structural region. The different folding status accounts for the different backbone dynamic and urea-unfolding transition features of the three fragments. The G-20I/G-29I-mutant variants of the three fragments have provided the evidence that the folding status is correlated closely to the packing of the beta-strands in the beta-barrel of the fragments. The native-like beta-barrel structural region acts as a nonlocal nucleus for folding the fragment. The tertiary folding of the three fragments is initiated by formation of the local nucleation sites at two beta-turn regions, I-18-D-21 and Y-27-Q-30, and developed by the formation of a nonlocal nucleation site at the beta-barrel region. The formation of beta-barrel and overall structure is concerted, but the level of cooperativity is different for the three 1-110 residues SNase fragments.

PubMed: 17172296
DOI: 10.1529/biophysj.106.092155

Experimental method

SOLUTION NMR