Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. II. Effect of glucose. J. Bacteriol. 84:988-995. 1962.-The effect of glucose and other compounds on the formation of tryptophanase and tryptophan synthetase in Escherichia coli was examined. Although most of these compounds were potent inhibitors of...

In 1903 Hopkins and Cole (1) identified tryptophan as the source of indole produced by bacterial cultures. The tryptophan-inducible enzyme responsible for this conversion, which is found most commonly in Escherichia coli, was subsequently named tryptophanase by Happold and Hoyle (2). Wood, Gunsalus, and Umbreit (3) showed that tryptophanase catalyzed the stoichiometric conversion of tryptophan ...

Freundlich, Martin (University of Minnesota, Minneapolis) and Herman C. Lichstein. Tryptophanase-tryptophan synthetase systems in Escherichia coli. III. Requirements for enzyme synthesis. J. Bacteriol. 84:996-1006. 1962.-The requirements for the formation of tryptophanase and tryptophan synthetase in Escherichia coli during repression release were studied. The kinetics of the formation of trypt...

Enteropathogenic Escherichia coli(EPEC) requires the tnaA-encoded enzyme tryptophanase and its substrate tryptophan to synthesize diffusible exotoxins that kill the nematode Caenorhabditis elegans. Here, we demonstrate that the RNA-binding protein CsrA and the tryptophan permease TnaB coregulate tryptophanase activity, through mutually exclusive pathways, to stimulate toxin-mediated paralysis a...

Tryptophanase, an enzyme with extreme absolute stereospecificity for optically active stereoisomers, catalyzes the synthesis of l-tryptophan from l-serine and indole through a beta-substitution mechanism of the ping-pong type, and has no activity on d-serine. We previously reported that tryptophanase changed its stereospecificity to degrade d-tryptophan in highly concentrated diammonium hydroge...

Tryptophanase from Bacillus alvei exhibited the expected spectrum of pyridoxal-5'-phosphate-dependent reactions. It exhibited l-serine dehydratase, S-alkyl-cysteine lyase, and cysteine desulfhydrase activities, as well as the classic tryptophanase reactions (all beta elimination reactions). It also acted as a tryptophan synthetase (beta replacement reactions) using indole plus l-serine or l-cys...

Cyclic 3’,5’-AMP stimulates the rate of tryptophanase synthesis in Escherichia coli treated with tris(hydroxymethyl)aminomethane and ethylenediaminetetraacetic acid and induced with tryptophan. A maximal effect occurs at 4 X low4 M cyclic 3’,5’-AMP and a half-maximal response at 1.5 X lo-4 M. The action of cyclic 3’,5’-AMP is specific for tryptophanase since the over-all rate of protein and RNA...

Repression of tryptophanase (tryptophan indole-lyase) by glucose and its non-metabolizable analogue methyl alpha-glucoside has been studied employing a series of isogenic strains of Escherichia coli lacking cyclic AMP phosphodiesterase and altered for two of the proteins of the phosphoenolpyruvate:sugar phosphotransferase system (PTS), Enzyme I and Enzyme IIAGlc. Basal activity of tryptophanase...

Expression of the tryptophanase (tna) operon in Escherichia coli is regulated by catabolite repression and transcription attenuation. Elevated levels of tryptophan induce transcription antitermination at one or more Rho factor-dependent termination sites in the leader region of the operon. Induction requires translation of a 24-residue coding region, tnaC, located in the 319-nucleotide transcri...