title: L-arabinose isomerase formation in a conditional mutant of gene araA of Escherichia coli B-r.
abstract: A temperature-sensitive mutant of Escherichia coli in which the synthesis of l-arabinose isomerase is blocked during growth at 42 C was found to possess the following properties. (i) The mutation occurred in the structural gene for the isomerase, gene araA. (ii) During growth at elevated temperatures the mutant accumulates a product which is a precursor to the active enzyme. (iii) The precursor produced at 42 C is slowly converted to active enzyme at 28 C in the absence of protein and ribonucleic acid synthesis. It is concluded that the mutation results in a change in the structure of isomerase which causes formation of active enzyme to be thermolabile at a step beyond the level of translation.
mesh_terms: D001089:Arabinose; D001426:Bacterial Proteins / Q000096:biosynthesis; D002474:Cell-Free System; D002701:Chloramphenicol / Q000494:pharmacology; D004792:Enzyme Precursors / Q000096:biosynthesis; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D005796:Genes; D005816:Genetic Complementation Test; D006358:Hot Temperature; D007535:Isomerases / Q000096:biosynthesis* / Q000378:metabolism; D009154:Mutation; D010770:Phosphotransferases / Q000378:metabolism; D012329:RNA, Bacterial / Q000096:biosynthesis; D013237:Stereoisomerism; D014161:Transduction, Genetic
chemical_list: D001426:Bacterial Proteins; D004792:Enzyme Precursors; D012329:RNA, Bacterial; D002701:Chloramphenicol; D001089:Arabinose; D010770:Phosphotransferases; D007535:Isomerases