RRC ID 35322
Author Kim J, Kershner JP, Novikov Y, Shoemaker RK, Copley SD.
Title Three serendipitous pathways in E. coli can bypass a block in pyridoxal-5'-phosphate synthesis.
Journal Mol Syst Biol
Abstract Bacterial genomes encode hundreds to thousands of enzymes, most of which are specialized for particular functions. However, most enzymes have inefficient promiscuous activities, as well, that generally serve no purpose. Promiscuous reactions can be patched together to form multistep metabolic pathways. Mutations that increase expression or activity of enzymes in such serendipitous pathways can elevate flux through the pathway to a physiologically significant level. In this study, we describe the discovery of three serendipitous pathways that allow synthesis of pyridoxal-5'-phosphate (PLP) in a strain of E. coli that lacks 4-phosphoerythronate (4PE) dehydrogenase (PdxB) when one of seven different genes is overexpressed. We have characterized one of these pathways in detail. This pathway diverts material from serine biosynthesis and generates an intermediate in the normal PLP synthesis pathway downstream of the block caused by lack of PdxB. Steps in the pathway are catalyzed by a protein of unknown function, a broad-specificity enzyme whose physiological role is unknown, and a promiscuous activity of an enzyme that normally serves another function. One step in the pathway may be non-enzymatic.
Volume 6
Pages 436
Published 2010-11-30
DOI 10.1038/msb.2010.88
PII msb201088
PMID 21119630
PMC PMC3010111
MeSH Carbohydrate Dehydrogenases / genetics Carbohydrate Dehydrogenases / physiology Epistasis, Genetic / physiology Escherichia coli / enzymology Escherichia coli / genetics* Escherichia coli / growth & development Escherichia coli / metabolism* Escherichia coli Proteins / genetics Escherichia coli Proteins / physiology Gene Expression Regulation, Bacterial / drug effects Gene Expression Regulation, Enzymologic / drug effects Genes, Bacterial / physiology Glucose / pharmacology Metabolic Networks and Pathways / genetics* Metabolic Networks and Pathways / physiology Microbiological Techniques Models, Biological Organisms, Genetically Modified Oxidoreductases / genetics Oxidoreductases / metabolism Pyridoxal Phosphate / biosynthesis* Serine / biosynthesis
IF 8.991
Times Cited 69
Prokaryotes E. coli ME9062(BW25113)(Keio) JW0890-KC JW0051-KC JW2548-KC JW1630-KC