Information Technology Reference
In-Depth Information
6
Information Gate
Kenichi Wakabayashi and
Masayuki Yamamura
Information exchange between cellular compartments allows us to engineer
systems based around cooperative principles. In this chapter we consider a
unique bacterial communication system, the conjugative plasmid transfer of
Enterococcus faecalis
. Using these bacteria, we describe how to engineer a
logically controlled information gate and build a logical inverter based upon it.
INTRODUCTION
Cellular computing is an alternative computing paradigm based on living cells
[1]. Microscale organisms, especially bacteria, are well suited for computing for
several reasons. A small culture provides an almost limitless supply of bacterial
“hardware.” Bacteria can be stored and easily modified by gene recombination.
In addition, and important for our purposes, bacteria can produce various signal
molecules that are useful for computation.
DNA-binding proteins recognize specific regulatory regions of DNA, bind
them, and regulate their genetic expression. These proteins are available for use
as computing signals inside the cell. Weiss et al. [8] have shown, for example,
how to construct logic circuits based on gene expression regulated by DNA-
binding proteins (see also chapter 4).
Some signal molecules are associated with intercellular communications
between individuals. Intercellular communication is one of the fundamental
characteristics of multicellular organisms, but it is also found in single-celled
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