title: SUPPRESSION OF A LAC O-O MUTATION IN ESCHERICHIA COLI.
abstract: Schwartz, Norman M. (Yale University, New Haven, Conn.). Suppression of a lac o degrees mutation in Escherichia coli. J. Bacteriol. 88:996-1001. 1964.-A class of pro(-) markers which can be cotransduced with lac map close to the i side of the lac region. The relative order of markers transferred by Hfr H is thr leu proA proB lac proC ade. Nine of ten slowgrowing lactose-utilizing revertants of a lac o degrees mutant are suppressed mutants. The time of entry of su-lac o-5 from an Hfr H derivative is 27 min. Su-lac o-5 is separated from the lac region by a 10-min interval. Su-lac o-5 is unstable, restores 7% of the wild-type level of beta-galactosidase activity, suppresses a try(-) mutation, and has a deleterious effect upon growth rate. The primary lac o degrees mutation is interpreted as being a z(-) polarity mutation which constitutes nonsense. Su-lac o-5 could act at the level of messenger ribonucleic acid translation converting nonsense to sense by promoting mistakes in protein synthesis.
mesh_terms: D004926:Escherichia coli; D005696:Galactosidases; D007785:Lactose; D009154:Mutation; D011506:Proteins / Q000378:metabolism*; D012313:RNA; D012333:RNA, Messenger; D012106:Research; D001616:beta-Galactosidase
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D012313:RNA; D005696:Galactosidases; D001616:beta-Galactosidase; D007785:Lactose
keywords: ESCHERICHIA COLI; EXPERIMENTAL LAB STUDY; GALACTOSIDASE; LACTOSE; MUTATION; PROTEIN METABOLISM; RNA, MESSENGER