Sensitivity of OR in phage lambda.
We investigate the sensitivity of the right operator in bacteriophage lambda. In particular, the system is probed in the three different regulatory protein concentration-regimes: 1), lysogen (CI dominates); 2), during induction (CI and Cro at comparable concentrations); and 3), after induction (Cro dominates). Systematic perturbations of the protein-operator binding energies show in a lysogen that the activity (production rate) at promoter PRM is robust to variations, in contrast to PR, where the sensitivity is high. Both promoters, however, show large sensitivity in regimes 2 and 3. In all regimes we identify several suppressors, meaning that for a given large perturbation (+/-2 kcal/mol) of one binding energy, there exist compensating perturbation(s) that restore the wild-type activity.
Bakk
Audun
A
NORDITA (Nordic Institute for Theoretical Physics), DK-2100 Copenhagen, Denmark. audunba@nordita.dk
Metzler
Ralf
R
Sneppen
Kim
K
D010582:Bacteriophage lambda / Q000737:chemistry*; D001665:Binding Sites; D003198:Computer Simulation; D004268:DNA-Binding Proteins / Q000737:chemistry*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry*; D004789:Enzyme Activation; D007700:Kinetics; D008956:Models, Chemical; D009875:Operator Regions, Genetic; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins
D004268:DNA-Binding Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; C016649:phage repressor proteins; D012321:DNA-Directed RNA Polymerases