Genetic selection for mutations that impair the co-operative binding of lambda repressor.
Bacteriophage lambda repressor binds co-operatively to adjacent pairs of DNA target sites. A novel combination of positive genetic selections, involving two different operon fusions derived from P22 challenge phages, was used to isolate mutant lambda repressors that have lost the ability to bind co-operatively to tandem sites yet retain the ability to bind a strong, single site. These cb (co-operative binding) mutations result in 10 different amino acid changes, which define eight residues in the carboxyl-terminus of repressor. Because challenge phage derivatives may be applied to study essentially any specific protein-DNA interaction, analogous combinations of genetic selections may be used to explore the ways that a variety of proteins interact to assemble regulatory complexes.
Benson
N
N
Department of Biological Sciences, University of Southern California, Los Angeles 90089-1481.
Adams
C
C
Youderian
P
P
D000595:Amino Acid Sequence; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D009838:Oligodeoxyribonucleotides; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics*; D012641:Selection, Genetic; D014157:Transcription Factors / Q000235:genetics*; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
D004268:DNA-Binding Proteins; D009838:Oligodeoxyribonucleotides; D012097:Repressor Proteins; D014157:Transcription Factors; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins