Team:Wisconsin-Madison/encryption

Description

Abstract

Sequential logic switches are the basis for many common electronic devices such as digital clocks and calculators. Here we present a novel design for the imitation of sequential logic using basic genetic parts within E. Coli. By using a combination of DNA recombinase enzymes, promoter systems, and an innovative pattern of recombinase binding sites, we can reproduce sequential-logical functions on the compact molecular scale. By using single DNA molecules as a medium for such functions within bacterial vehicles, we can essentially mimic the functionality of a combination lock, and produce a "locked" gene which can be effectively "unlocked" only after a specific sequence of inputs detected by the bacterial promoter system. Since the DNA molecule is used as a logical medium, the "locked" and "unlocked" states are effectively heritable to subsequent bacterial cell lines, which would make such a system useful as the computational basis for many higher-order genetic devices from bacterial calculators to engineering of new metabolic pathways to bacterial drug delivery systems.

Background

Recombination

Site-specific DNA recombination can occur in a number of ways resulting in deletion, inversion, or insertion of DNA. The recombination event requires a recombinase protein and a pair of enzyme-specific DNA recombination sites. Sometimes a host-factor or a enhancer sequence is required in addition to the recombinase and the recognition sites for the recombination event to occur.

The Parts Registry also has a page devoted to DNA Recombination.

Two-plasmid System

Our system utilizes two plasmids. One plasmid acts as the recombinase producer (called the "key"). The other acts as the medium for recombination (called the "lock").

Parts

The Key Plasmid

The Key Plasmid produces recombinase enzymes based upon specific chemical inputs. These enzymes recognize the recombination sites on the "locked" plasmid and alter the DNA.

The Lock Plasmid

The Lock Plasmid provides the medium for the recombinases produced by the "key" while maintaining a "locked" promoter region thereby controlling expression of genes attached to the "lock." The lock only becomes unlocked after a specific pattern of recombination events, and the Lock Plasmid is passed on to future generations of bacteria.