Differential scanning calorimetry study of the thermodynamic stability of some mutants of Sso7d from Sulfolobus solfataricus.


Abstract

Sso7d from the thermoacidophilic archaebacterium Sulfolobus solfataricus is a small globular protein with a known three-dimensional structure. Inspection of the structure reveals that Phe31 is a member of the aromatic cluster forming the protein hydrophobic core, whereas Trp23 is located on the protein surface and its side chain exposed to the solvent. The thermodynamic consequences of the substitution of these two residues in Sso7d have been investigated by comparing the temperature-induced denaturation of Sso7d with that of three mutants: F31A-Sso7d, F31Y-Sso7d, and W23A-Sso7d. The denaturation processes proved to be reversible for all proteins, and represented well by the two-state N if D transition model in a wide range of pH. All three mutants are less thermally stable than the parent protein; in particular, in the pH range of 5.0-7.0, the F31A substitution leads to a decrease of 24 degreesC in the denaturation temperature, the F31Y substitution to a decrease of 10 degreesC, and the W23A substitution to a decrease of 6 degreesC. A careful thermodynamic analysis of such experimental data is carried out. Study holds ProTherm entries: 9453 Extra Details: thermoacidophilic; aromatic cluster; hydrophobic core;,thermodynamic analysis

Submission Details

ID: gBs7QicC3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:38 p.m.

Version: 1

Publication Details
Catanzano F;Graziano G;Fusi P;Tortora P;Barone G,Biochemistry (1998) Differential scanning calorimetry study of the thermodynamic stability of some mutants of Sso7d from Sulfolobus solfataricus. PMID:9671520
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
1B4O 1998-12-24T00:00:00+0000 0 NMR STUDY OF SSO7D MUTANT (F31A) MINIMIZED AVERAGE STRUCTURE
1JIC 1998-07-20T00:00:00+0000 0 SOLUTION NMR STRUCTURE OF RECOMBINANT SSO7D WITH RNASE ACTIVITY, MINIMIZED AVERAGE STRUCTURE
1SSO 1995-03-31T00:00:00+0000 0 SOLUTION STRUCTURE AND DNA-BINDING PROPERTIES OF A THERMOSTABLE PROTEIN FROM THE ARCHAEON SULFOLOBUS SOLFATARICUS

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
93.2 DNA-binding protein 7a Q96X56 DN7_SULTO
98.4 DNA-binding protein 7a F0NJT3 DN7B_SULIH
96.9 DNA-binding protein 7d O59632 DN7B_SACSH
100.0 DNA-binding protein 7a D2PHL8 DN7A_SULID
100.0 DNA-binding protein 7a P61990 DN7A_SACSH
100.0 DNA-binding protein 7a P61991 DN7A_SACS2
100.0 DNA-binding protein 7d P39476 DN7D_SACS2