Defective in vitro binding of histidyl-transfer ribonucleic acid to feedback resistant phosphoribosyl transferase of Salmonella typhimurium.
We previously proposed that the first enzyme for histidine biosynthesis in Salmonellatyphimurium plays a role in regulating expression of the histidine operon and that in order to play this role the enzyme must form a complex with histidyl-tRNA. Among the many observations that led to these conclusions were 1) that regulation of the histidine operon is defective in strains carrying a mutation in the gene for the first enzyme that renders the enzyme resistant to inhibition by histidine; and 2) that the enzyme purified from the wild type strain interacts specifically, and with high affinity, with histidyl-tRNA. The present study was carried out to test the prediction that the enzyme purified from the mutant strain described above would display a defect in its interaction with histidyl-tRNA. This prediction was fulfilled by the finding that purified histidine-insensitive enzyme does not bind histidyl-tRNA. Our results therefore suggest that the capacity of the enzyme to bind histidyl-tRNA invitro is a reflection of its regulatory function invivo.
Smith
O
O
Meyers
M M
MM
Vogel
T
T
Deeley
R D
RD
Goldberger
R
R
D005246:Feedback; D005798:Genes, Bacterial; D006639:Histidine / Q000096:biosynthesis / Q000235:genetics; D009154:Mutation; D009876:Operon; D010430:Pentosyltransferases / Q000235:genetics / Q000378:metabolism*; D012329:RNA, Bacterial / Q000378:metabolism*; D012354:RNA, Transfer, His / Q000378:metabolism*; D012486:Salmonella typhimurium / Q000235:genetics / Q000378:metabolism*
D012329:RNA, Bacterial; D012354:RNA, Transfer, His; D006639:Histidine; D010430:Pentosyltransferases