Decoding of genetic information occurs upon interaction of an mRNA codon-tRNA anticodon complex with the small subunit of the ribosome. The ribosomal decoding region is associated with highly conserved sequences near the 3' end of 16 S rRNA. The decoding process is perturbed by the aminoglycoside antibiotics, which also interact with this region of rRNA. Mutations of certain nucleotides in rRNA...

The photochemical modification of 16 S rRNA by longwave ultraviolet light in the presence of hydroxymethyltrimethyl psoralen (HMT) produces uridine-psoralen adducts. Psoralenmodified 16 S rRNA is primed with a 3’-proximal restriction fragment and copied with reverse transcriptase. The average length of the cDNA transcripts decreases as the number of covalently bound psoralen adducts on the temp...

Helix 34 of 16 S rRNA is located in the head of the 30 S ribosomal subunit close to the decoding center and has been invoked in a number of ribosome functions. In the present work, we have studied the effects of mutations in helix 34 both in vivo and in vitro. Several nucleotides in helix 34 that are either highly conserved or form important tertiary contacts in 16 S rRNA (U961, C1109, A1191, a...

The Bacillus stearothermophilus ribosomal protein S15 (BS15) binds both a three-helix junction in the central domain of 16 S ribosomal RNA and its cognate mRNA. Native gel mobility-shift assays show that BS15 interacts specifically and with high affinity to the 5'-untranslated region (5'-UTR) of this cognate mRNA with an apparent dissociation constant of 3(+/-0.3) nM. In order to localize the s...