A new RNA branching activity: the GIR1 ribozyme.
The formation of lariat intermediates during the first step of splicing of group II introns and spliceosomal introns is a well-studied fundamental reaction in molecular biology. Apart from this prominent example, there are surprisingly few occurrences of branched nucleotides or even 2',5'-phosphodiester bonds in biology. We recently described a new ribozyme, the GIR1 branching ribozyme, which catalyzes the formation of a tiny lariat that caps an mRNA. This new example together with work on artificial branching ribozymes and deoxyribozymes shows that branching is facile and points to the possibility that branching reactions could be more prevalent than previously recognized.
Nielsen
Henrik
H
Department of Medical Biochemistry and Genetics, The Panum Institute, University of Copenhagen, Denmark. hamra@imbg.ku.dk
Johansen
Steinar D
SD
D002384:Catalysis; D021881:DNA, Catalytic; D009690:Nucleic Acid Conformation; D012313:RNA / Q000737:chemistry*; D012315:RNA Caps; D016337:RNA, Catalytic / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology
D021881:DNA, Catalytic; C116167:GIR1 ribozyme; D012315:RNA Caps; D016337:RNA, Catalytic; D012313:RNA