Thermodynamics of staphylococcal nuclease denaturation. II. The A-state.


Abstract

Staphylococcal nuclease, at low pH and in the presence of high salt concentrations, has previously been proposed to exist in a partially folded or molten globule form called the "A-state" (Fink et al., 1993, Protein Sci 2:1155-1160). We have found that the A-state of nuclease at pH 2.1 in the presence of moderate to high salt concentrations and at low temperature exists in a substantially folded form structurally more similar to a native state. The A-state has the far-UV circular dichroism spectra characteristic of the native protein, which indicates that it has a large degree of secondary structure. Upon heating, the A-state denatures with a sigmoidal change in far-UV ellipticity and an observable peak in a differential scanning calorimeter trace, indicating that it is thermodynamically distinct from the denatured state. Three different mutations in a residue normally buried in the protein's core stabilize or destabilize the A-state in the same way as they affect the denaturation of the native state. The A-state must, therefore, contain at least some tertiary packing of side chains. Unlike the native state, which shows cold denaturation at low temperatures, the A-state is most stable at temperatures below 0 degrees C. Study holds ProTherm entries: 2778, 2779, 2780, 2781, 2782 Extra Details: additive : EDTA(1 mM), denatured state; molten globule; protein denaturation;,structural intermediate; unfolding

Submission Details

ID: sh3cs8YZ

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:19 p.m.

Version: 1

Publication Details
Carra JH;Anderson EA;Privalov PL,Protein Sci. (1994) Thermodynamics of staphylococcal nuclease denaturation. II. The A-state. PMID:8069224
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 PDB Entries

Structure ID Release Date Resolution Structure Title
4WRD 2014-10-23T00:00:00+0000 1.65 Crystal structure of Staphylcoccal nulease variant Delta+PHS V66E L125E at cryogenic temperature
2LKV 2011-10-21T00:00:00+0000 0 Staphylococcal Nuclease PHS variant
2M00 2012-10-14T00:00:00+0000 0 Solution structure of staphylococcal nuclease E43S mutant in the presence of ssDNA and Cd2+
2OXP 2007-02-20T00:00:00+0000 2.0 Crystal Structure of Staphylococcal Nuclease mutant V66D/P117G/H124L/S128A
3D4W 2008-05-15T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant Delta+PHS A109R at cryogenic temperature
3D8G 2008-05-23T00:00:00+0000 1.99 Crystal structure of Staphylococcal nuclease variant Delta+PHS I72R at cryogenic temperature
3MVV 2010-05-04T00:00:00+0000 1.72 Crystal structure of Staphylococcal nuclease variant Delta+PHS F34A at cryogenic temperature
3QOJ 2011-02-10T00:00:00+0000 1.6 Cryogenic structure of Staphylococcal nuclease variant D+PHS/V23K
3QOL 2011-02-10T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant D+PHS/V23E at pH 6 determined at 100 K
3R3O 2011-03-16T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant Delta+PHS T62A at cryogenic temperature and with high redundancy

Relevant UniProtKB Entries

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