Comparative structural analysis of eubacterial 5S rRNA by oxidation of adenines in the N-1 position

Adenines in free 5S rRNA from Escherichia coli, Bacillus stearothermophilus and Thermus thermophilus have been oxidized at their N-1 position using monoperphthalic acid. The determination of the number of adenine 1-N-oxides was on the basis of UV spectroscopic data of the intact molecule. Identification of the most readily accessible nucleotides by sequencing gel analysis reveals that they are located in conserved positions within loops, exposed hairpin loops and single-base bulge loops. Implications for the structure and function of 5S rRNA will be discussed on the basis of this comparative analysis.