title: Influence of Escherichia coli DnaK and DnaJ molecular chaperones on tryptophanase (TnaA) amount and GreA, GreB stability.
abstract: The amount of tryptophanase was estimated in Escherichia coli deltadnaJ and deltadnaKdnaJ mutants. Densitometric analysis of polyacrylamide gels demonstrated that the amount of tryptophanase was diminished in both mutants. DnaK and DnaJ molecular chaperones apparently influence the amount of tryptophanase, the expression of which is regulated at all transcription steps, including transcription elongation. The half-life of GreA and GreB proteins (being activators of transcription elongation of the tna operon) are diminished in both mutants suggesting the involvement of DnaK and DnaJ in the stability of these proteins.
authors.affiliation: Department of Bacterial Genetics, Institute of Microbiology, University of Warsaw, 02 096 Warsaw, Poland. grudam@biol.uw.edu.pl
authors.forename: A M
authors.initials: AM
authors.lastname: Grudniak
authors.forename: B
authors.initials: B
authors.lastname: Nowicka-Sans
authors.forename: M
authors.initials: M
authors.lastname: Maciag
authors.forename: K I
authors.initials: KI
authors.lastname: Wolska
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression; D005798:Genes, Bacterial; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006207:Half-Life; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D014157:Transcription Factors / Q000378:metabolism*; D035602:Transcriptional Elongation Factors; D014368:Tryptophanase / Q000235:genetics / Q000378:metabolism*
chemical_list: C494635:DnaJ protein, E coli; D029968:Escherichia coli Proteins; C079668:GreA protein, E coli; C079667:GreB protein, E coli; D050956:HSP40 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D014157:Transcription Factors; D035602:Transcriptional Elongation Factors; C063842:dnaK protein, E coli; D014368:Tryptophanase