Thermostability of the barnase-barstar complex.


Abstract

Scanning microcalorimetry was used to study heat denaturation of barnase in complex with its intracellular inhibitor barstar. The heat denaturation of the barnase-barstar complex is well approximately by two two-state transitions with the lower temperature transition corresponding to barstar denaturation and the higher temperature one to barnase denaturation. The temperature of barnase melting in its complex with barstar is 20 degrees C higher than that of the free enzyme. The barstar melting temperature is almost the same in the complex or alone (71 degrees C at pH 6.2 and 68 degrees C at pH 8.0). It seems possible that when barstar unfolds it can remain bound to barnase, while the latter unfolds only on dissociation of the denatured barstar. Study holds ProTherm entries: 10386, 10387 Extra Details: barnase-barstar complex; heat denaturation; scanning microcalorimetry;,isothermal microcalorimetry

Submission Details

ID: cxAM5esa

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:40 p.m.

Version: 1

Publication Details
Makarov AA;Protasevich II;Lobachov VM;Kirpichnikov MP;Yakovlev GI;Gilli RM;Briand CM;Hartley RW,FEBS Lett. (1994) Thermostability of the barnase-barstar complex. PMID:7957933
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
1A2P 1998-01-07T00:00:00+0000 1.5 BARNASE WILDTYPE STRUCTURE AT 1.5 ANGSTROMS RESOLUTION
1B20 1998-12-03T00:00:00+0000 1.7 DELETION OF A BURIED SALT-BRIDGE IN BARNASE
1B21 1998-12-03T00:00:00+0000 2.0 DELETION OF A BURIED SALT BRIDGE IN BARNASE
1B27 1998-12-04T00:00:00+0000 2.1 STRUCTURAL RESPONSE TO MUTATION AT A PROTEIN-PROTEIN INTERFACE
1B2S 1998-11-30T00:00:00+0000 1.82 STRUCTURAL RESPONSE TO MUTATION AT A PROTEIN-PROTEIN INTERFACE
1B2U 1998-12-01T00:00:00+0000 2.1 STRUCTURAL RESPONSE TO MUTATION AT A PROTEIN-PROTEIN INTERFACE
1B2X 1998-12-03T00:00:00+0000 1.8 BARNASE WILDTYPE STRUCTURE AT PH 7.5 FROM A CRYO_COOLED CRYSTAL AT 100K
1B2Z 1998-12-03T00:00:00+0000 2.03 DELETION OF A BURIED SALT BRIDGE IN BARNASE
1B3S 1998-12-01T00:00:00+0000 2.39 STRUCTURAL RESPONSE TO MUTATION AT A PROTEIN-PROTEIN INTERFACE
1BAN 1993-05-19T00:00:00+0000 2.2 THE CONTRIBUTION OF BURIED HYDROGEN BONDS TO PROTEIN STABILITY: THE CRYSTAL STRUCTURES OF TWO BARNASE MUTANTS

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
97.3 Ribonuclease P35078 RN_BACCI
100.0 Ribonuclease P00648 RNBR_BACAM