30S subunits were isolated capable to bind simultaneously two molecules of Phe-tRNAPhe (or N-Acetyl-Phe-tRNAPhe), both poly(U) dependent. The site with higher affinity to tRNA was identified as P site. tRNA binding to this site was not inhibited by low concentrations of tetracycline (2 x 10(-5)M) and, on the other hand, N-Acetyl-Phe-tRNAPhe, initially prebound to the 30S.poly(U) complex in the ...

A DNA fragment of 487 bp containing a gene for tRNAPhe has been sequenced. Although the tRNAPhe sequence is identical to that of pheU (which maps at 94.5 min) the surrounding sequences are quite different. This sequence is thus that of a second gene for tRNAPhe (which we shall call pheV). In vitro transcription experiments and S1 mapping in vivo show the existence of two promoters separated by ...

We have isolated and sequenced a tRNAPhe gene from Neurospora crassa. Hybridization analyses suggest that trnaPhe is the only tRNA encoded on the cloned 5 kb DNA fragment. The tRNAPhe gene contains an intervening sequence 16 nucleotides in length located one nucleotide 3' to the anticodon position. The tRNAPhe coding region of Neurospora and yeast are 91% conserved, whereas their intervening se...

The minor base 3-(3-amino-3-carboxypropyl)uridine (acp3U) in Escherichia coli tRNAPhe was acylated with the N-hydroxysuccinimide esters of acetic, phenoxy-acetic, and naphthoxyacetic acid, as well as the ester of 5-dimethylaminonaphthalene-1-sulfonyl (dansyl)-glycine. The derivatives of tRNAPhe formed were all capable of accepting phenylalanine. There were only minor effects on the kinetic para...

The fluorescence decay functions of individual, specifically labeled tRNAPhe molecules exhibit nonexponential character as a result of conformational dynamics occurring during the measurement on a single molecule. tRNAPhe conformational states that interchange much more slowly are evidenced by the distribution of lifetimes observed for many individual molecules. A structural model for the nonex...

A discrete primary transcript of HeLa mitochondrial DNA containing 12 S rRNA, tRNAPhe, and 19 +/- 2 nucleotides upstream has been identified. The 5' ends of heavy strand encoded RNAs adjacent to the D-loop region of mitochondrial DNA were mapped by primer extension and S1 nuclease protection to a site 19 +/- 2 nucleotides upstream from the start of tRNAPhe. Hybridization of a tRNAPhe-specific p...

Treatment of Escherichia coli CA265 phenylalanyl-tRNA with 3M-NaHSO3, pH6.0, at 25 degrees C resulted in modification of four bases and in the deacylation of the charged tRNAphe. The similarity of the rates of base modification and of the deacylation of the phenylalanyl-tRNA permitted the isolation of partially modified phenylalanyl-tRNAphe and partially modified deacylated tRNAphe. The sites a...

Vero cells, a line derived from African green monkey kidney, contains a hypermodified base, called Y, adjacent to the 3' end of the anticodon of tRNAPhe. Two types of evidence are presented suggesting that lysine is involved in biosynthesis of Y base in these cells. First, when Vero cells are starved for lysine, a new, early-eluting species of tRNAPhe which lacks the fully modified Y base can b...

The question of whether or not the tRNA at the third ribosomal binding site specific for deacylated tRNA (E site) undergoes codon-anticodon interaction was analyzed as follows. Poly(U)-programmed ribosomes each carrying two [14C]tRNAPhe molecules were subjected to a chasing experiment using various tRNA species. At 0 degree C Ac[3H]Phe-tRNAPhe did not trigger any chasing whereas deacylated cogn...

Yeast phenylalanine tRNA (tRNAPhe) exhibits a 4$-fold enhancement of fluorescence in response to the addition of Mg2+. Concurrently, over the same concentration range (0 to 0.4 m&r) of Mg2+, the circular dichroism peak at 263 nm displays a 20% increase in ellipticity and a blue shift of 2 nm. The existence of the negative circular dichroism band at 295 nm appears to be cation-dependent. This co...