Binding of A-R2 to OA' operator

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The ScbA-ScbR complex (AR2) binds to the alternative ScbA gene operator (OA') and activates its maximum mRNA transcription.

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Chemical equation

O_{A}' + AR_{2} \rightleftharpoons O_{A}'-AR_{2}

Rate equation

 r= \frac{k^{-}_{5}}{K_{d5}}\cdot [O_{A}']\cdot [AR_{2}] - k^{-}_{5}\cdot [O_{A}'-AR_{2}]

Parameters

The parameters of this reaction are the dissociation constant for binding of ScbA-ScbR to OA' (K_{d5}) and the dissociation rate for binding of ScbA-ScbR to OA' (k^{-}_{5}).

Name Value Units Origin Remarks
K_{d5} 0.1 - 5.6 [1] [2] [3]  nM TetR-tetO interaction and

TetR-like Rv3066 from M. tuberculosis

The values were chosen by assuming that the interaction would be within the same

range of strength as the ScbR-OA (without the complex).

k^{-}_{5} 0.6-1.2 [4] [5]  min^{-1} SPR of a TetR-like protein (RolR) on a Gram and

GC content ~ 50-60% from Corynebacterium glutamicum

Parameters with uncertainty

The most plausible parameter value for the K_{d5} is decided to be  5 nM and the confidence interval  1.1 . This means that the mode of the PDF is 5 and the range where 95% of the values are found is between 4.55 and 5.5 nM.

In a similar way, the most plausible value for k^{-}_{5} is 0.9 min^{-1} and the confidence interval 1.3. This means that the mode of the PDF is 0.9 and the range where 95% of the values are found is between 0.6923 and 1.17 min^{-1}.

The probability distributions for the two parameters, adjusted accordingly in order to reflect the above values, are the following:

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The location and scale parameters of the distributions are:

Parameter μ σ
K_{d5} 1.6118 0.04834
k^{-}_{5} -0.0878 0.1327

References

  1. Kamionka A, Bogdanska-Urbaniak J, Scholz O, Hillen W. Two mutations in the tetracycline repressor change the inducer anhydrotetracycline to a corepressor. Nucleic Acids Research. 2004;32(2):842-847.
  2. Bolla JR, Do SV, Long F, et al. Structural and functional analysis of the transcriptional regulator Rv3066 of Mycobacterium tuberculosis. Nucleic Acids Research. 2012;40(18):9340-9355.
  3. Ahn SK, Tahlan K, Yu Z, Nodwell J. Investigation of Transcription Repression and Small-Molecule Responsiveness by TetR-Like Transcription Factors Using a Heterologous Escherichia coli-Based Assay. Journal of Bacteriology. 2007;189(18):6655-6664.
  4. Sylwia Kedracka-Krok, Andrzej Gorecki, Piotr Bonarek, and Zygmunt Wasylewski. Kinetic and Thermodynamic Studies of Tet Repressor−Tetracycline Interaction. Biochemistry 2005 44 (3), 1037-1046.
  5. Li T, Zhao K, Huang Y, et al. The TetR-Type Transcriptional Repressor RolR from Corynebacterium glutamicum Regulates Resorcinol Catabolism by Binding to a Unique Operator, rolO. Applied and Environmental Microbiology. 2012;78(17):6009-6016.