Team:BYU Provo/Modeling

Overview

AND Gate

In other fields such as electrical or software engineering, logic gates form the foundation of decision-making circuits. Our project was to build a simple logic gate in E. coli from modular molecular parts. This year we built an AND gate. An AND gate works by only producing an output in the presence of two inputs. In the figure to the right, "A" and "B" are the inputs, and "Y" is the output. In this case, If either A, B, or both inputs are missing, then "Y" will not be expressed.

Our molecular AND gate works by the same principle as conventional AND gates. Input "A" in our construct can be held by any regulated promoter. In testing our construct we used two promoters: Pbad (a common, arabinose-inducible promoter) and PsoxS (a naturally occurring, reactive oxygen species-inducible promoter). Input "B" in our construct is a temperature dependent RNA switch or "thermosensor". Ouput "Y" can be any reporter gene. We have alternately used lacZ (turns blue in presence of X-gal), Superfolder GFP (fluoresces green), and an iGEM enzyme that produces [http://partsregistry.org/wiki/index.php?title=Part:BBa_J45270 banana smell].

Modeling the AND gate is similar for any combination of parts. To simplify this discussion, assume the Pbad promoter (an "arabinose" sensor"), the wild-type Lysteria thermosensor (a "heat" sensor), and GFP (our reporter or "output").

Molecular AND Gate Function