A model of the changes in denatured state structure underlying m value effects in staphylococcal nuclease.


Hydrogen exchange kinetics were measured on the native states of wild type staphylococcal nuclease and four mutants with values of mGuHCl (defined as dDeltaG/d[guanidine hydrochloride]) ranging from 0.8 to 1.4 of the wild type value. Residues within the five-strand beta-barrel of wild type and E75A and D77A, two mutants with reduced values of m GuHCl, were significantly more protected from exchange than expected on the basis of global stability as measured by fluorescence. In contrast, mutants V23A and M26G with elevated values of mGuHCl approach a flat profile of more or less constant protection independent of position in the structure. Differences in exchange protection between the C-terminus and the beta-barrel region correlate with mGuHCl, suggesting that a residual barrel-like structure becomes more highly populated in the denatured states of m- mutants and less populated in m+ mutants. Variations in the population of such a molten globule-like structure would account for the large changes in solvent accessible surface area of the denatured state thought to underlie m value effects. Study holds ProTherm entries: 7024, 7025, 7026, 7027, 7028, 7029, 7030, 7031, 7032, 7033, 7034, 7035, 7036, 7037, 7038 Extra Details: hydrogen exchange kinetic; five-strand beta-barrel;,global stability; solvent accessible surface area; m value

Submission Details

ID: u3jvLBc83

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:32 p.m.

Version: 1

Publication Details
Wrabl J;Shortle D,Nat. Struct. Biol. (1999) A model of the changes in denatured state structure underlying m value effects in staphylococcal nuclease. PMID:10467101
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Thermonuclease P00644 NUC_STAAU
99.3 Thermonuclease Q5HHM4 NUC_STAAC
99.1 Thermonuclease Q99VJ0 NUC_STAAM
99.1 Thermonuclease Q7A6P2 NUC_STAAN
99.3 Thermonuclease Q6GB41 NUC_STAAS
99.3 Thermonuclease Q8NXI6 NUC_STAAW
99.3 Thermonuclease Q6GIK1 NUC_STAAR