Derepressed Levels of the Isoleucine-Valine and Leucine Enzymes in hisT1504, a Strain of Salmonella typhimurium with Altered Leucine Transfer Ribonucleic Acid
AUTOR(ES)
Rizzino, A. A.
RESUMO
A hisT mutant of Salmonella typhimurium was found to have altered regulation of the isoleucine-valine and leucine enzymes. These enzymes in the hisT strain were derepressed two- to eightfold over those of the parent wild-type strain when grown in minimal medium or under repressing conditions. The amount of tRNALeu and the cellular concentration of charged tRNALeu was about the same in the hisT strain and in the wild type. However, leucyl-tRNA from the mutant was chromatographically different from that of wild type, confirming previous reports that hisT strains have altered tRNALeu. These results suggest strongly that tRNALeu is involved in repression of the isoleucine-valine and leucine enzymes in S. typhimurium.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=285533Documentos Relacionados
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