  The DevRS two component system of Mycobacterium tuberculosis is responsible
for its dormancy in host and becomes operative under hypoxic condition. It is
experimentally known that phosphorylated DevR controls the expression of
several downstream genes in a complex manner. In the present work we propose a
theoretical model to show role of binding sites in DevR mediated gene
expression. Individual and collective role of binding sites in regulating DevR
mediated gene expression has been shown via modeling. Objective of the present
work is two fold. First, to describe qualitatively the temporal dynamics of
wild type genes and their known mutants. Based on these results we propose that
DevR controlled gene expression follows a specific pattern which is efficient
in describing other DevR mediated gene expression. Second, to analyze behavior
of the system from information theoretical point of view. Using the tools of
information theory we have calculated molecular efficiency of the system and
have shown that it is close to the maximum limit of isothermal efficiency.
