title: Strain of Escherichia coli with a temperature-sensitive mutation affecting ribosomal ribonucleic acid accumulation.
abstract: A mutant of Escherichia coli has been isolated that has a temperature-sensitive mutation that results in specific loss of ribosomal ribonucleic acid (RNA) synthesis and some reduction in messenger RNA synthesis. When the strain was grown in glucose medium at a restrictive temperature, RNA accumulation ceased, but both messenger RNA and protein synthesis continued for an extended time. Because carbon metabolism was slowed drastically when strain AA-157 was placed at the restrictive temperature, this phenotype can be compared with carbon depletion conditions present during diauxic lag. However, the phenotype of mutant AA-157 differs from shift-down conditions in that guanosine-3',5'-tetraphosphate levels are unaffected; therefore, a different site is affected. This mutant strain (AA-157) thus shows many characteristics similar to an aldolase mutant previously reported (Böck and Neidhardt, 1966). However, the mutation occurred in a different position on the E. coli genetic map, and furthermore, aldolase was not temperature sensitive in strain AA-157. In this paper we present a study of macromolecular biosynthesis in this mutant.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis; D003433:Crosses, Genetic; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism*; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006150:Guanine Nucleotides / Q000096:biosynthesis; D009153:Mutagens; D009154:Mutation; D009604:Nitrosoguanidines; D009693:Nucleic Acid Hybridization; D010649:Phenylalanine / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis*; D012333:RNA, Messenger / Q000096:biosynthesis; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D011995:Recombination, Genetic; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D014529:Uridine / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D006150:Guanine Nucleotides; D009153:Mutagens; D009604:Nitrosoguanidines; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D010649:Phenylalanine; D005634:Fructose-Bisphosphate Aldolase; D005947:Glucose; D014529:Uridine