title: Transfer of a gene for sucrose utilization into Escherichia coli K12, and consequent failure of expression of genes for D-serine utilization.
abstract: As the first stage in investigating the genetic basis of natural variation in Escherichia coli, the gene(s) conferring the ability to use sucrose as a carbon and energy source (given the symbol sac+) was transferred from a wild strain to K12, which does not use sucrose. The sac+ region was transferred by two different methods. On both occasions it took a chromosomal location at minute 50.5 on the linkage map, between aroC and supN, in the region of the dsd genes, which confer the ability to use D-serine as a carbon  and energy source. When the sac+ region was present in the K12 chromosome the bacteria were unable to use D-serine as a carbon and energy source. In F' sac+/dsd+ diploids, the dsd+ genes were similarly not expressed. Strain K12(sac+) bacteria were sensitive to inhibition by D-serine; they mutated to D-serine resistance with much greater frequency than did a dsd mutant of K12. Such bacteria also mutated frequently to use raffinose. Strain K12(sac+) bacteria did not utilize sucrose when they carried a mutation affecting the phosphotransferase system.
mesh_terms: D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D005796:Genes; D008040:Genetic Linkage; D011815:R Factors; D012694:Serine / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism*; D014161:Transduction, Genetic
chemical_list: D012694:Serine; D013395:Sucrose