Long-chain fatty acid transport in Escherichia coli. Cloning, mapping, and expression of the fadL gene.
Transport of long-chain fatty acids across the inner membrane of Escherichia coli K-12 requires a functional fadL gene (Maloy, S. R., Ginsburgh, C. L., Simons, R. W., and Nunn, W. D. (1981) J. Biol. Chem. 256, 3735-3742). Mutants defective in the fadL gene lack a 33,000-dalton inner membrane protein as evaluated using two-dimensional pI/sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis (Ginsburgh, C. L., Black, P. N., and Nunn, W. D. (1984) J. Biol. Chem. 259, 8437-8443). In an effort to determine whether the fadL gene is the structural gene for this 33,000-dalton protein, we have cloned, mapped, and analyzed the expression of the fadL gene. The fadL gene has been localized on a 2.8-kilobase EcoRV fragment of E. coli genomic DNA. Plasmids containing this gene (i) complement all fadL mutants, (ii) increase the long-chain fatty acid transport activity of fadL strains harboring them by 2- to 3-fold, and (iii) direct the synthesis of a membrane protein which has the same molecular weight and isoelectric point as that described by Ginsburgh et al. This is a heat-modifiable protein which has an apparent molecular weight of 43,000 daltons when solubilized at 100 degrees C in the presence of SDS and 33,000 daltons when solubilized at 50 degrees C in the presence of SDS.
D001426:Bacterial Proteins / Q000235:genetics; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D005796:Genes; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics; D008970:Molecular Weight; D009154:Mutation; D010957:Plasmids
D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D005227:Fatty Acids; D008565:Membrane Proteins