Biophysical evidence of arm-domain interactions in AraC.
We report development of a method for the direct measurement of the interaction between the N-terminal arm and the remainder of the dimerization domain in the Escherichia coli AraC protein, the regulator of the l-arabinose operon. The interaction was measured using surface plasmon resonance to monitor the association between the immobilized peptide arm and the dimerization domain, truncated of its arm, in solution. As expected from genetic and physiological data, the interaction is strongly stimulated by l-arabinose and is insensitive to sugars like d-glucose or d-galactose. Alterations in the sequence of the arm which physiological experiments predict either to strengthen or weaken the arm produce the expected responses.
Ghosh
M
M
Biology Department, Johns Hopkins University, 3400 North Charles Street, Baltimore, Maryland 21218, USA.
Schleif
R F
RF
D000595:Amino Acid Sequence; D051777:AraC Transcription Factor; D001089:Arabinose / Q000378:metabolism; D001426:Bacterial Proteins; D055592:Biophysical Phenomena; D001703:Biophysics; D019281:Dimerization; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D005690:Galactose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D008969:Molecular Sequence Data; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry* / Q000378:metabolism*; D020349:Surface Plasmon Resonance / Q000379:methods*; D014157:Transcription Factors
D051777:AraC Transcription Factor; C497371:AraC protein, E coli; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D001089:Arabinose; D005947:Glucose; D005690:Galactose