Isolation of tRNA isoacceptors by affinity chromatography with immobilized elongation factor Tu from Escherichia coli.
Elongation factor Tu (EF-Tu) from E. coli was coupled to activated CH Sepharose 4B. The immobilized EF-Tu maintained most of the guanosine nucleotide binding activity, but its ability to bind aminoacyl-tRNA depended on the type of complex used in the coupling reaction. The EF-Tu.GTP.aminoacyl-tRNA.kirromycin complex yielded an immobilized factor that was much more active in binding aminoacyl-tRNA than that obtained by coupling EF-Tu.GDP or EF-Tu.GDP.kirromycin to CH Sepharose 4B. Like the free factor, the immobilized EF-Tu.GTP did bind aminoacyl-tRNAs, but not unacylated tRNAs or N-acylated-aminoacyl-tRNAs. The antibiotic kirromycin was used to obtain the rapid conversion of EF-Tu.GDP to EF-Tu.GTP and the release of aminoacyl-tRNA from the matrix-bound EF-Tu by GDP. When total tRNA was aminoacylated by one amino acid only, a column of immobilized EF-Tu-GTP.kirromycin allowed the isolation of the aminoacylated tRNA from bulk tRNA. A rapid and nearly quantitative recovery of highly purified tRNA isoacceptors for various amino acids was obtained in one chromatographic step.
Chinali
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Dipartimento de Medicina Clinica e Sperimentale, Facoltà di Medicina e Chirurgia, Università di Napoli Federico II, Italy.
D002846:Chromatography, Affinity / Q000379:methods*; D004926:Escherichia coli; D005069:Evaluation Studies as Topic; D006160:Guanosine Triphosphate; D008024:Ligands; D010444:Peptide Elongation Factor Tu; D011728:Pyridones; D012346:RNA, Transfer, Amino Acyl / Q000302:isolation & purification*; D012685:Sepharose
D008024:Ligands; D011728:Pyridones; D012346:RNA, Transfer, Amino Acyl; D006160:Guanosine Triphosphate; D012685:Sepharose; D010444:Peptide Elongation Factor Tu; C008536:mocimycin