The induction of tRNA synthesis following T4 phage infection

✍ Scribed by Uriel Z. Littauer; Violet Daniel

• Publisher: John Wiley and Sons
• Year: 1969
• Tongue: English
• Weight: 838 KB
• Volume: 74
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040740406

✦ Synopsis

T4 bacteriophage infection of E. colz B cells induces the formation of 4 s RNA molecules that specifically hybridize with T4 DNA. The T4 4 s RNA extracted from the hybrid was found to contain pseudouridylic acid, suggesting that some of this RNA might have amino acid acceptor function. I n order to study the amino acid acceptor capacity of the T4 4 s RNA, two procedures were devised. The first one involved the isolation and purification of specific 4 s RNA-DNA hybrids in a manner that avoided the use of RNase and permitted the extraction of biologically active tRNA from the hybrid. It was found that a significant fraction of the T4 4s RNA isolated by this method had amino acid acceptor activity. This was shown by assaying with a mixture of 15 14C-labeled amino acids or with C14Clleucine alone.

In the second method, T4 N-acetylC3H1aminoacyl-tRNA was prepared in order to stabilize the aminoacyl-tRNA ester bond. T4 N-acetyll3Hlleucyl-tRNA was incubated with T4 DNA in the presence of 50% formamide at 30°C. Sephadex G-200 chromatog raphy revealed that a significant fraction of the N-acetylC3H Jleucyl-tRNA hybridized with the T4 DNA. Another procedure involved the hybridization of N-acetyll3HIaminoacyl-tRNA with T4 DNA at 70°C in a citrate buffer in the absence of formamide. The annealing mixture also contained a &&fold excess of uncharged E. coEi tRNA. The hybrid-containing solution was loaded onto nitrocellulose filters and treated with T1 RNase. At this point, the T4 tRNA was found to contain leucine-, arginine-, isoleucine-, and possibly tyrosine-specific chains.

* From Daniel et al. ('68a).

t Between the GMP and UMP peaks, two small peaks containing 0.6 and 0.43% of the total label were : Including qMP.

found. However, they did not correspond to either peak Y or peak %MP.