title: Interaction between histidyl transfer ribonucleic acid and the first enzyme for histidine biosynthesis of Salmonella typhimurium.
abstract: Previous studies showed that the enzyme (phosphoribosyltransferase) which catalyzes the first step of the histidine pathway in Salmonella typhimurium plays a role in regulation of the histidine operon. Since histidyl transfer ribonucleic acid (His-tRNA) is required for repression of the histidine operon, we considered the possibility that the role of phosphoribosyltransferase might be realized through an interaction with His-tRNA. One prediction inherent in this idea is that the enzyme should interact with His-tRNA in vitro. Evidence is presented for such an interaction. Binding of (3)H-His-tRNA to purified phosphoribosyltransferase was tested on Sephadex columns and on nitrocellulose filters. The enzyme was found to have a high affinity for tRNA. Comparing the binding of (3)H-His-tRNA with that of tRNA aminoacylated with other (3)H-amino acids disclosed that the binding of the histidyl species of tRNA is favored over that of other species and is dependent upon magnesium-ion concentration.
mesh_terms: D000179:Acrylates; D000596:Amino Acids / Q000378:metabolism; D002247:Carbon Isotopes; D002845:Chromatography; D004586:Electrophoresis; D005374:Filtration; D005782:Gels; D006639:Histidine / Q000096:biosynthesis*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009711:Nucleotides / Q000378:metabolism; D011485:Protein Binding; D012343:RNA, Transfer / Q000302:isolation & purification; D012486:Salmonella typhimurium / Q000201:enzymology / Q000378:metabolism*; D014166:Transferases / Q000302:isolation & purification; D014316:Tritium
chemical_list: D000179:Acrylates; D000596:Amino Acids; D002247:Carbon Isotopes; D005782:Gels; D009711:Nucleotides; D014316:Tritium; D006639:Histidine; D012343:RNA, Transfer; D014166:Transferases; D008274:Magnesium