DNA specificity determinants of Escherichia coli tryptophan repressor binding.
We have analyzed the sequence-specific interaction between the Escherichia coli tryptophan (Trp) repressor and its operator using challenge phage vectors. These phages, derivatives of Salmonella phage P22 that have substitutions of synthetic, symmetric trp operators for the P22 mnt operator, provide a genetic assay for DNA binding in vivo. Phages carrying operators that retain the determinants of Trp repressor binding efficiently lysogenize cells producing repressor; in contrast, phages with operators missing critical determinants kill such hosts. The binding determinants revealed by this assay corroborate a simple docking model for the Trp repressor-operator interaction postulated from the repressor crystal structure, and account for both the specificity of repressor binding and the ability of Trp repressor to recognize multiple, tandem DNA sites.
Bass
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S
Department of Biological Sciences, University of Southern California, Los Angeles 90089-1481.
Sugiono
P
P
Arvidson
D N
DN
Gunsalus
R P
RP
Youderian
P
P
D001426:Bacterial Proteins; D001483:Base Sequence; D001665:Binding Sites; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D009876:Operon; D010957:Plasmids; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D012483:Salmonella Phages / Q000235:genetics*; D012486:Salmonella typhimurium / Q000235:genetics*; D014157:Transcription Factors / Q000378:metabolism*; D029968:Escherichia coli Proteins
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D012097:Repressor Proteins; D014157:Transcription Factors; C027190:TRPR protein, E coli; D029968:Escherichia coli Proteins