Metabolic Pathways in E. coli to Make Alcohols

[morkriddare]

Hi everyone!

 

I am a FR1 Biochemistry student in Michigan and this is my first post on this forum. I hope you guys will be able to help me figure out some metabolic pathways in E. coli.

 

I am writing a paper on the production of long-chain alcohols by E. coli. The main reference that I'm using is a paper by Zhang, Liao and others of UCLA (http://www.pnas.org/content/105/52/20653.full.pdf+html?sid=1d98aadd-4d83-402b-aa5c-f0bf12e0ff53). These researchers have modified E. coli's lac operon and have added KIVD and ADH6 genes, as well as overexpressing genes already present in the bacterium.

 

I know there are a lot of different pathways that interact to make the alcohols: glycolysis, pyruvate dehydrogenation, β-oxidation, formation of keto acids, etc. However, I am having a very hard time understanding how these all relate to one another. I think I understand the last steps: keto acids, the precursors of amino acids, are decarboxylated and dehydrogenated by the enzymes produced by KIVD and ADH6 to form alcohols. How do we go from glucose and pyruvate to keto acids, though? And how does this new method make longer chains of alcohol than what used to be available (5-carbon alcohol)?

 

Any help you can give me will be greatly appreciated.

 

Thank you!

[CharonY]

So let's see. Your problem is the connections of glucose and pyruvate? Well how do you go from glucose to pyruvate (essentially you answered it in your post yourself).

Now pyruvate is well connected to other pathways. What is the central hub in biochemical pathways in almost all organisms?

From there it is a relatively small step to find the intermediates to go all the way down to the various alcohols.