Effect of N-terminal deletions on the foldability, stability, and activity of staphylococcal nuclease.
The effect of N-terminally successive deletions on the foldability, stability, and activity of staphylococcal nuclease was examined. The structural changes in the nuclease caused by the deletions follow a hierarchical pattern: N-terminal truncation of the nuclease by up to nine residues clearly perturbs the conformation of the N-terminal beta-subdomain but does not affect the C-terminal alpha-subdomain; deletion of 11 or 12 residues perturbs the C-terminal alpha-subdomain, resulting in formation of a molten globule state; deletion of 13 residues causes the nuclease to become highly unfolded. N-terminally deleted nuclease delta11 retains the ability to fold but delta12 is not able to fold into an enzymatically active conformation, suggesting that 11 residues is the maximum length that can be deleted from the N-terminus while still retaining the folding competence of the nuclease. Further, the results suggest that proper folding of the C-terminal alpha-subdomain probably relies on the integrity of the N-terminal beta-subdomain.
Zhang
Hongjie
H
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica, Beijing 100101, PR China.
Huang
Sun
S
Feng
Yanming
Y
Guo
Peng
P
Jing
Guozhong
G
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D003198:Computer Simulation; D004789:Enzyme Activation; D004795:Enzyme Stability; D008836:Micrococcal Nuclease / Q000032:analysis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D014508:Urea / Q000737:chemistry
D014508:Urea; D008836:Micrococcal Nuclease