Biochemical studies on the DNA binding function of the cyclic-amp reactor protein of Escherichia coli

Thesis/Dissertation · Tue Dec 31 23:00:00 EST 1985

OSTI ID:6792171

Angulo, J A

The cAMP receptor protein (CRP) is an allosteric protein in which binding of cAMP effects a conformational change with a consequent increased affinity for DNA. Binding of double-stranded deoxyribopolynucleotides and calf thymus DNA by cAMP-CRP confers protection against attack by trypsin, subtilisin, Staph. aureus V8 protease and clostripain. Of the single-stranded deoxy- and ribopolynucleotides tested, only r(I)/sub n/ and r(A)/sub n/ gave significant protection against attack by these proteases. In the absence of cAMP, CRP is resistant to proteolysis. Incubation of CRP-DNA with trypsin results in the accumulation of two novel fragments. CRP-DNA is partially sensitive to digestion by chymotrypsin but resistant to attack by subtilisin, the Staph. aureus V8 protease and clostripain. Cleavage of CRP-DNA to fragments is accompanied by the loss of /sup 3/H-cAMP binding activity. Modification of the arginines with phenylglyoxal or butanedione results in loss of DNA binding activity. cAMP-CRP incorporates more /sup 14/C-phenylglyoxal than unliganded CRP. Titration of the arginines with /sup 14/C-phenylglyoxal to where over 90% of the DNA binding activity is lost results in incorporation of one mole of reagent per mole of subunit.

• Research Organization: City Univ. of New York, NY (USA)
• OSTI ID: 6792171
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMP
BACTERIA
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
CARBON 14 COMPOUNDS
CHEMICAL REACTIONS
CHEMISTRY
CONFIGURATION INTERACTION
DECOMPOSITION
DNA
ENZYMATIC HYDROLYSIS
ESCHERICHIA COLI
HYDROLYSIS
KINETICS
LABELLED COMPOUNDS
LYSIS
MEMBRANE PROTEINS
MICROORGANISMS
NUCLEIC ACIDS
NUCLEOTIDES
ORGANIC COMPOUNDS
PROTEINS
REACTION KINETICS
RECEPTORS
SOLVOLYSIS
TRITIUM COMPOUNDS