Scanning calorimetric study of the thermal unfolding of catabolite activator protein from Escherichia coli in the absence and presence of cyclic mononucleotides.


Abstract

The thermal unfolding of the catabolite activator protein (CAP) of Escherichia coli and the complexes it forms with adenosine cyclic 3',5'-phosphate (cAMP) and guanosine cyclic 3',5'-phosphate (cGMP) was studied by high-sensitivity differential scanning calorimetry (DSC). The thermal denaturation of CAP at pH 7.00 gave an irreversible, symmetrical denaturation curve with a single peak. Distinctly different, more complex DSC curves were obtained for the thermal denaturation of the cAMP-protein and cGMP-protein complexes. The DSC data indicate intermolecular cooperation among CAP dimers, with the extent of oligomerization remaining unchanged during unfolding of the protein. The DSC curves for the thermal denaturation of the cAMP-protein complex and cGMP-protein complex have been resolved into three and two components, respectively, according to the model of independent two-state processes. Analysis of the DSC data suggests two and three independent domains for cGMP-protein and cAMP-protein complexes, respectively, with dissociation of mononucleotide occurring in the second component in both cases during protein denaturation. Furthermore, our studies indicate that the presence of either ligand alters the degree of oligomerization of CAP dimers, cAMP having a greater effect than cGMP. Study holds ProTherm entries: 3845 Extra Details: additive : EDTA(0.2 mM), intermolecular cooperation; oligomerization;,three independent domains; protein denaturation

Submission Details

ID: MTJtwmvu3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:23 p.m.

Version: 1

Publication Details
Ghosaini LR;Brown AM;Sturtevant JM,Biochemistry (1988) Scanning calorimetric study of the thermal unfolding of catabolite activator protein from Escherichia coli in the absence and presence of cyclic mononucleotides. PMID:2844254
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
6B6H 2017-10-02T00:00:00+0000 3.9 The cryo-EM structure of a bacterial class I transcription activation complex
6PB6 2019-06-13T00:00:00+0000 4.29 The E. coli class-II CAP-dependent transcription activation complex at the state 2
6PB4 2019-06-13T00:00:00+0000 4.35 The E. coli class-II CAP-dependent transcription activation complex with de novo RNA transcript at the state 2
6PB5 2019-06-13T00:00:00+0000 4.52 The E. coli class-II CAP-dependent transcription activation complex at the state 1 architecture
1G6N 2000-11-07T00:00:00+0000 2.1 2.1 ANGSTROM STRUCTURE OF CAP-CAMP
3KCC 2009-10-21T00:00:00+0000 1.66 Crystal structure of D138L mutant of Catabolite Gene Activator Protein
4I0A 2012-11-16T00:00:00+0000 2.2 structure of the mutant Catabolite gene activator protein V132A
4I0B 2012-11-16T00:00:00+0000 1.5 structure of the mutant Catabolite gene activator protein H160L
3ROU 2011-04-26T00:00:00+0000 2.1 Domain-domain flexibility leads to allostery within the camp receptor protein (CRP)
1ZRE 2005-05-19T00:00:00+0000 2.8 4 crystal structures of CAP-DNA with all base-pair substitutions at position 6, CAP-[6G;17C]ICAP38 DNA

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
99.5 cAMP-activated global transcriptional regulator CRP P0A2T6 CRP_SALTY
99.5 cAMP-activated global transcriptional regulator CRP P0A2T7 CRP_KLEAE
100.0 cAMP-activated global transcriptional regulator CRP P0ACK1 CRP_SHIFL
100.0 cAMP-activated global transcriptional regulator CRP P0ACJ8 CRP_ECOLI
100.0 cAMP-activated global transcriptional regulator CRP P0ACJ9 CRP_ECOL6
100.0 cAMP-activated global transcriptional regulator CRP P0ACK0 CRP_ECO57