The properties of repressor and the kinetics of its action

Sadler, John R.; Novick, Aaron

doi:10.1016/s0022-2836(65)80255-8

Cited by 255 publications

(120 citation statements)

References 17 publications

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“…To determine the range, an approximate lower value of 10 4 nM was obtained from Ref. [28], and we allowed for an upper value of 10 6 nM to account for potential differences between induction by IPTG and TMG or lactose.…”

Section: Parameter Valuesmentioning

confidence: 99%

Determinants of bistability in induction of the Escherichia coli lac operon

et al. 2008

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We have developed a mathematical model of regulation of expression of the Escherichia coli lac operon, and have investigated bistability in its steady-state induction behavior in the absence of external glucose.Numerical analysis of equations describing regulation by artificial inducers revealed two natural bistability parameters that can be used to control the range of inducer concentrations over which the model exhibits bistability. By tuning these bistability parameters, we found a family of biophysically reasonable systems that are consistent with an experimentally determined bistable region for induction by thio-methylgalactoside (Ozbudak et al. Nature 427:737, 2004). The model predicts that bistability can be abolished when passive transport or permease export becomes sufficiently large; the former case is especially relevant to induction by isopropyl-β, D-thiogalactopyranoside. To model regulation by lactose, we developed similar equations in which allolactose, a metabolic intermediate in lactose metabolism and a natural inducer of lac, is the inducer. For biophysically reasonable parameter values, these equations yield no bistability in response to induction by lactose; however, systems with an unphysically small permease-dependent export effect can exhibit small amounts of bistability for limited ranges of parameter values. These results cast doubt on the relevance of bistability in the lac operon within the natural context of E. coli, and help shed light on the controversy among existing theoretical studies that address this issue. The results also suggest an experimental approach to address the relevance of bistability in the lac operon within the natural context of E. coli.

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Section: Parameter Valuesmentioning

confidence: 99%

Determinants of bistability in induction of the Escherichia coli lac operon

et al. 2008

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“…The tsf phenotype is not a general feature of temperature sensitive alleles in radial spoke proteins: cells carrying the R-84, allele of pf-1 (RSP4), for example, assemble spoke heads at 20°C but not 32°C; the flagella assembled at 20°C become paralyzed when shifted to 32°C [Huang et al, 19811. Thus, for the R-84, mutant, the protein within the spoke head is itself temperature sensitive; for the ~f -2 6 ,~ mutant, however, the temperature sensitive entity is an intermediate step in the pathway through which RSP6* is folded or assembled into the flagellum [Sadler and Novick, 1965;Villafane and King, 19881.…”

Section: Radial Spoke Assemblymentioning

confidence: 99%

Flagellar radial spoke: A model molecular genetic system for studying organelle assembly

Curry

Rosenbaum

1993

Cell Motil. Cytoskeleton

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“…Many ts proteins lose activity when shifted from permissive to nonpermissive temperatures, and many acquire activity when shifted from nonpermissive to permissive temperatures (5)(6)(7). Cold-sensitive mutants have been isolated in several organisms (8)(9)(10)(11)(12) plates, and buffered saline have been described (13).…”

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confidence: 99%