Binding cooperativity in phage lambda is not sufficient to produce an effective switch.
In the wild-type phage lambda, binding of CI to O(R)2 helps polymerase bound to P(RM) transition from a closed to open complex. Activators on other promoters increase the polymerase-DNA binding energy, or affect both the binding energy and the closed-open transition probability. Using a validated mathematical model, we show that these two modes of upregulation have very different effects on the promoter function. We predict that if CI(2) bound to O(R)2 produced equal increase in RNAP-DNA binding constant (compared to wild-type increase in the closed-open transition probability), the lysogen would be significantly less stable.
Gedeon
Tomás
T
Department of Mathematical Sciences, Montana State University, Bozeman, Montan, USA. gedeon@math.montana.edu
Mischaikow
Konstantin
K
Patterson
Kathryn
K
Traldi
Eliane
E
D010582:Bacteriophage lambda / Q000235:genetics* / Q000378:metabolism*; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D015967:Gene Expression Regulation, Viral; D008242:Lysogeny / Q000235:genetics; D008954:Models, Biological; D009154:Mutation; D009875:Operator Regions, Genetic / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism; D015203:Reproducibility of Results; D054334:Viral Regulatory and Accessory Proteins / Q000378:metabolism; D014775:Virus Activation / Q000235:genetics* / Q000502:physiology*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D012321:DNA-Directed RNA Polymerases