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Lariat formation and a hydrolytic pathway in plant chloroplast group II intron splicing
Author(s) -
Vogel Jörg,
Börner Thomas
Publication year - 2002
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/cdf359
Subject(s) - biology , intron , rna splicing , group ii intron , chloroplast , genetics , group i catalytic intron , group (periodic table) , microbiology and biotechnology , botany , evolutionary biology , computational biology , gene , rna , chemistry , organic chemistry
Lariat formation has been studied intensively only with a few self‐splicing group II introns, and little is known about how the numerous diverse introns in plant organelles are excised. Several of these introns have branch‐points that are not a single bulge but are adjoined by A:A, A:C, A:G and G:G pairs. Using a highly sensitive in vivo approach, we demonstrate that all but one of the barley chloroplast introns splice via the common pathway that produces a branched product. RNA editing does not improve domain 5 and 6 structures of these introns. The conserved branch‐point in tobacco rpl16 is chosen even if an adjacent unpaired adenosine is available, suggesting that spatial arrangements in domain 6 determine correct branch‐point selection. Lariats were not detected for the chloroplast trnV intron, which lacks an unpaired adenosine in domain 6. Instead, this intron is released as linear molecules that undergo further polyadenylation. trnV , which is conserved throughout plant evolution, constitutes the first example of naturally occurring hydrolytic group II intron splicing in vivo .