title: Spermidine synthase of Escherichia coli: localization of the speE gene.
abstract: We have obtained Escherichia coli mutants lacking spermidine synthase (putrescine aminopropyltransferase) and have found that the mutated gene (speE) is located immediately upstream from the gene coding for S-adenosylmethionine decarboxylase (speD); these genes are located at 2.7 minutes on the E. coli chromosome. Both genes are present in a 1795-base-pair fragment of E. coli DNA that was cloned into pBR322. Deletion of 105 bases upstream of speE caused a coordinate loss of both activities, indicating that speE and speD constitute a single operon. speE and speD have also been cloned separately in a high-expression vector; strains carrying these plasmids overproduce the respective enzymes.
mesh_terms: D012437:Adenosylmethionine Decarboxylase / Q000235:genetics; D002872:Chromosome Deletion; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005798:Genes, Bacterial; D005838:Genotype; D009876:Operon; D010957:Plasmids; D013045:Species Specificity; D011436:Spermidine Synthase / Q000235:genetics*; D014166:Transferases / Q000235:genetics*
chemical_list: D014166:Transferases; D011436:Spermidine Synthase; D012437:Adenosylmethionine Decarboxylase