The linker region of AraC protein.
AraC protein, a transcriptional regulator of the L-arabinose operon in Escherichia coli, is dimeric. Each monomer consists of a domain for DNA binding plus transcription activation and a domain for dimerization plus arabinose binding. These are connected to one another by a linker region of at least 5 amino acids. Here we have addressed the question of whether any of the amino acids in the linker region play active, specific, and crucial structural roles or whether these amino acids merely serve as passive spacers between the functional domains. We found that all but one of the linker amino acids can be changed to other amino acids individually and in small groups without substantially affecting the ability of AraC protein to activate transcription when arabinose is present. When, however, the entire linker region is replaced with linker sequences from other proteins, the functioning of AraC is impaired.
Eustance
R J
RJ
Biology Department, Johns Hopkins University, Baltimore, Maryland 21218, USA.
Schleif
R F
RF
D000595:Amino Acid Sequence; D051777:AraC Transcription Factor; D001426:Bacterial Proteins; D001483:Base Sequence; D001665:Binding Sites; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D008969:Molecular Sequence Data; D016296:Mutagenesis; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D014157:Transcription Factors
D051777:AraC Transcription Factor; C497371:AraC protein, E coli; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D012097:Repressor Proteins; D014157:Transcription Factors