Bioinformatics-Guided Identification and Experimental Characterization of Novel RNA Methyltransferas.

Naturally occurring RNAs contain numerous chemically altered nucleosides. They are formed by enzymatic modification of the primary transcripts during the complex RNA maturation process. To date, a total of 96 structurally distinguishable modified nucleosides originating from different types of RNAs from many diverse organisms of the three major phylogenetic domains of life have been reported (Rozenski et al. 1999); http://medstat.med.utah.edu/RNAmods; and references therein). The pattern of modifications (type and location) depends on the RNA molecule considered, as well as, on the organism or the organelle they originate from.However, the largest number of modified nucleosides with the greatest structural diversity (a total of 81) is found in transfer RNAs, especially in tRNAs from higher organisms (Sprinzl et al. 1998; http://www.uni-bayreuth.de/departments/biochemie/trna). Other types of RNA (snRNA, snoRNA, rRNA,mRNA) also contain modified nucleosides (see http://rna.wustl.edu/snoRNAdb), however, their occurrence and particularly their diversity are lower than in tRNAs (see, for example,Limbach et al. 1995;Motorin and Grosjean 1998). [ABSTRACT FROM AUTHOR]