Genetic control of arylsulfatase synthesis in Klebsiella aerogenes

Abstract

It was shown that at least four genes are specifically responsible for arylsulfatase synthesis inKlebsiella aerogenes. Mutations at chromosome site atsA result in enzymatically inactive arylsulfatase. Mutants showing constitutive synthesis of arylsulfatase (atsR) were isolated by using inorganic sulfate or cysteine as the sulfur source. Another mutation in which repression of arylsulfatase by inorganic sulfate or cysteine could not be relieved by tyramine was determined by genetic analysis to be on the tyramine oxidase gene (tyn). This site was distinguished from the atsC mutation site, which is probably concerned with the action or synthesis of corepressors of arylsulfatase synthesis. Genetic analysis with transducing phage PW52 showed that the order of mutation sites was atsC-atsR-atsA-tynA-tynB. On the basis of these results and previous physiological findings, we propose a new model for regulation of arylsulfatase synthesis.

Regulation of derepressed synthesis of arylsulfatase by tyramine oxidase in Salmonella typhimurium

“…The syntheses ofboth enzymes were repressed when the cells were grown on glucose with ammonium chloride even in the presence of tyra- (2,9).…”

“…To elucidate the genetic regulation of arylsulfatase synthesis, we chose K. aerogenes W70, since E. coli K-12 and S. typhimurium LT2, the bacterial strains most widely used in genetic analyses, produce little or no arylsulfatase under normal conditions. On the basis of genetic studies using the general transducing phage PW52 and introducing the coliphage P1 or F' episomes into K. aerogenes, we proposed a model of genetic regulation of arylsulfatase synthesis (9). Furthermore, in immunological studies we showed that there is a similar regulation system of arylsulfatase synthesis in enteric bacteria (12,21) and in intergeneric hybrid strains between K. aerogenes and E. coli or S. typhimurium (11).…”

“…In this paper, we show that arylsulfatase from S. typhimurium LT2 differs greatly from the enzyme of K. aerogenes (17) and Serratia marcescens (13) in its Km and V.. values. Comparative studies on the regulation of the syntheses of tyramine oxidase and arylsulfatase and genetic studies on mutant strains, such as tynA, tynP, or tynP tynR, in K. aerogenes led us to the interesting conclusion that the apparent level of derepressed synthesis of arylsulfatase by tyramine under conditions of catabolite and ammonium repression is just a reflection of the regulation pattem of tyramine oxidase synthesis (9,14,16). The experiments reported here clearly show that the regulation of arylsulfatase synthesis in S. typhimurium is similar to that in K. aerogenes, except for the effect of methionine, although this idea has been strongly challenged by others (7).…”

“…Arylsulfatase synthesis in Klebsiella aerogenes is repressed by a repressor molecule (atsR) that has been activated by a corepressor, such as inorganic sulfate, cysteine, or related compounds, and this repression is relieved by the addition of tyramine (1,2). Recently, by using tyramine oxidase-deficient (tynA) and tyramine oxidase-constitutive (tynP tynR) mutants, we demonstrated that the expression of tyramine oxidase induced by tyramine results in derepression of the atsA gene specifying arylsulfatase, which is closely linked to tynA (9,14,16). Tyramine and catechol amines are oxidized by tyramine oxidase to hydroxyphenylacetoaldehyde compounds and ammonium ions, and the enzyme synthesis is subject to catabolite and ammonium repressions (9,15,18).…”

“…Recently, by using tyramine oxidase-deficient (tynA) and tyramine oxidase-constitutive (tynP tynR) mutants, we demonstrated that the expression of tyramine oxidase induced by tyramine results in derepression of the atsA gene specifying arylsulfatase, which is closely linked to tynA (9,14,16). Tyramine and catechol amines are oxidized by tyramine oxidase to hydroxyphenylacetoaldehyde compounds and ammonium ions, and the enzyme synthesis is subject to catabolite and ammonium repressions (9,15,18). Intergeneric hybrid strains, formed by transfer of the ats and tyn genes between Escherichia coli, Salmonella typhimurium, and Citrobacter freundii suggested that the system of regulation of arylsulfatase synthesis in enteric bacteria is conserved more than the structure (11,12) or function of enzyme protein during evolution (21).…”