Biology Reference
In-Depth Information
Fig. 10. A screenshot of GON.
Simulation Results of five mutants of the lac operon
The five mutants taken into consideration in this simulation are listed below together with the realization
methods of the mutants in the HFPN model of Fig. 8.
lacZ
−
a mutant which can not produce
β
-galactosidase,
•
delete the transition
T
67
,
lacY
−
a mutant which can not produce
β
-galactoside permease,
•
delete the transition
T
70
,
lacI
−
a mutant in which 4 repressor monomers can not constitute one active repressor tetramer,
•
delete the transition
T
59
,
lacI
s
a mutant to which allolactose can not bind,
•
delete the transitions
T
77
and
T
78
together with the inhibitory arc from the place “allolactose”
to the transition
T
64
,
lacI
−d
a mutant which can not bind to the DNA,
•
delete the transitions
T
60
and
T
61
.
Behavior of the wild type
In both of Figs 11 and 12, the concentration behaviors of lactose (outside of a cell), lactose, glucose,
LacZ (
β
-galactosidase), and LacY (
β
-galactoside permease) are shown. From the beginning, glucose is
degraded, since it is consumed in the glycolytic pathway. At time point 55, the glucose was consumed,
the transcription of lac operon begins, producing the LacZ protein (time
=
60), and successively, LacY
