title: Isolation of chromosomal mutations that affect carotenoid production in Escherichia coli: mutations alter copy number of ColE1-type plasmids.
abstract: Chromosomal mutants were isolated in Escherichia coli that altered carotenoid production from transformed carotenoid biosynthesis genes on a pACYC-derived plasmid (pPCB15). The mutations were mapped by sequencing. One group of mutations appeared to affect the cell metabolism without changing the copy number of the carotenoid synthesis plasmid. The other group of mutations either increased or decreased the copy number of the pPCB15 plasmid as determined by real-time PCR. The copy number change in most mutants was likely specific for ColE1-type plasmids for which copy number is controlled by a small antisense RNA. This collection of host strains would be useful for fine tuning expression of proteins and adjusting production of desired molecules without recloning to different vectors.
authors.affiliation: Biological and Chemical Sciences and Engineering, Central Research and Development, E.I. DuPont de Nemours Inc., Wilmington, DE 19880-0328, USA.
authors.forename: Luan
authors.initials: L
authors.lastname: Tao
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Jackson
authors.forename: Pierre E
authors.initials: PE
authors.lastname: Rouvière
authors.forename: Qiong
authors.initials: Q
authors.lastname: Cheng
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001709:Biotechnology / Q000379:methods; D002338:Carotenoids / Q000096:biosynthesis*; D002876:Chromosomes, Bacterial / Q000235:genetics; D004251:DNA Transposable Elements; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D018628:Gene Dosage; D015964:Gene Expression Regulation, Bacterial; D016254:Mutagenesis, Insertional; D009154:Mutation; D010957:Plasmids
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; C042833:ROM protein, Bacteria; D002338:Carotenoids