O2'-Methylinosine, a constituent of the ribosomal RNA of Crithidia fasciculata.
A novel nucleoside, O2'-methylinosine (Im), has been identified as a constituent of the ribosomal RNA of Crithidia fasciculata, a hemoflaggelate protozoan. The nucleoside is released as part of an alkali-stable dinucleotide, Im-Up, by alkaline hydrolysis of Crithidia rRNA, and as a 5'-nucleotide, pIm, by snake venom hydrolysis of the same RNA. The Im-containing derivatives isolated from Crithidia rRNA were characterized by comparison with marker compounds prepared by chemical deamination of the corresponding adenosine analogues. O2'-Methylinosine prepared from either natural Im-Up or natural pIm had the same ultraviolet absorption spectra and chromatographic properties as marker Im. Characterization of the base and sugar components of Im as hypoxanthine and 2-O-methylribose, respectively, provided final confimration of structure. Control experiments have eliminated the possibility that Im arises from O2'-methyladenosine (Am), a known constituent of ribosomal RNA, by chemical or enzymatic deamination during hydrolysis of Crithidia rRNA.
D002854:Chromatography, Paper; D006863:Hydrogen-Ion Concentration; D007288:Inosine / Q000031:analogs & derivatives* / Q000302:isolation & purification; D012335:RNA, Ribosomal; D013056:Spectrophotometry, Ultraviolet; D014345:Trypanosoma / Q000032:analysis*
D012335:RNA, Ribosomal; D007288:Inosine