Isoleucine - Valine Requiring Mutants of Salmonella Typhimurium
نویسنده
چکیده
E have isolated a number of mutant strains of Salmonella typhimurium that display a marked inhibition of growth when valine is added to minimal medium. Attempts to elucidate the nature of the mutation(s) in these valinesensitive strains have included enzymatic and transductional analyses, as well as growth studies, on four of these strains. The results of these studies are presented and discussed in this report.
منابع مشابه
Isoleucine-valine requiring mutants of Salmonella typhimurium. II. Strains deficient in dihydroxyacid dehydratase activity.
MONG the available isoleucine-valine requiring strains of Salmonella t yphiA murium (termed ilu) are a number of mutants deficient in CY, p-dihydroxyacid dehydratase4 activity (ARMSTRONG and WAGNER 1964). The production of this enzyme is under the control of the iluD gene (WAGNER and BERGQUIST 1960). This report is concerned with transductional analyses that have been carried out using the iZuD...
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initial reports on the mutant strains of Salmonella typhimurium that T: eui r both isoleucine and valine for growth (ilva strains) were published concomitantly by GLANVILLE and DEMEREC ( 1960) and WAGNER and BERGQUIST (1960). These studies showed that although the available ilva strains could be divided into four complementation groups ( A , B , C and D ) on the basis of abortive transduction r...
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In a previous paper (Kiritani and Inuzuka 1970) , it was reported that Salmonella typhimurium mutants deficient in both the branched-chain-amino-acid aminotransferase EC 2.6.1.6 (transaminase B) and the a, j3-dihydroxyacid dehydratase EC 4.2.1.9 required leucine in addition to isoleucine and valine for normal growth, whereas the known mutants deficient in transaminase B require only isoleucine,...
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N microorganisms, a single mutation event can result in the growth require’ ment of two amino acids, isoleucine and valine. This is not considered unusual since the two amino acids share a common biosynthetic pathway (UMBARGER and DAVIS 1962), (Figure 1). In Salmonella typhimurium (GLANVILLE and DEMEREC 1960), the genes controlling the synthesis of the enzymes of the isoleucine-valine pathway a...
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