Difference between revisions of "Part:BBa K2032002"

Latest revision as of 17:30, 19 October 2016

Formate Pathway

Note: The FDH and FALDH parts in this pathway contain stop codons, unlike the source biobricks. Stop codons are necessary in this polycistronic expression system.

The Formate Pathway is a three enzyme pathway that begins with methanol and NAD+ as substrates, and culminates in the production of NADH molecules and carbon dioxide. This pathway is used to detoxify alcohols in the cellular environment. The pathway consists of a series of oxidations: methanol oxidized to formaldehyde by Methanol Dehydrogenase 2 (MDH2); formaldehyde oxidized to formate by Formaldehyde Dehydrogenase (FALDH); and finally formate oxidized to carbon dioxide by Formate Dehydrogenase (FDH). Each of these catalyzed reactions results in lower energy products than reactants, so every reaction is coupled to the production of one NADH molecule, which contributes to energy for the cell and biomass production. The first enzyme of the pathway, MDH2, has a low binding specificity and will oxidize many primary alcohols. The original use of this plasmid was to detoxify methanol as part of a larger pathway that consisted of eliminating methane gas from the atmosphere. The pathway has potential uses for detoxifying alcohols in the environment as well. As methanol becomes an increasingly popular liquid fuel source, one could imagine methanol spills in the future that require detoxification. This part contains one promoter that is IPTG inducible. The genes will be transcribed as a polycistronic mRNA strand. Each of the genes has a medium strength ribosome binding site.

Modeling of this pathway has revealed that no toxic substrates should be produced when this pathway is expressed. The kinetics for each enzyme exist in such a way that there will be no buildup of formaldehyde of formic acid in the cell. Theoretically, this pathway should increase methanol resistance to cells that express it.

Sequence and Features