Linked Life Data

9236120

Source:http://linkedlifedata.com/resource/pubmed/id/9236120

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1997-8-15
pubmed:databankReference
pubmed:abstractText
Group II introns frequently require assistance by specific factors, maturases, for folding and effective splicing in vivo. The only putative maturase of higher plant chloroplasts is encoded by matK, located in the intron of trnK. We show that in barley matK transcripts are modified at a first codon base by C-to-U RNA editing. The resulting H --> Y substitution restores a sequence motif that is present in maturases of yeast and plant mitochondria and of Lactococcus ltrA and that is positioned within the X domain. Processing of trnK-matK transcripts was further investigated in plastids lacking functional ribosomes due to a mutation. Absence of the intron-encoded matK gene product in these plastids is correlated with the accumulation of precursor transcripts for tRNALys(UUU)-matK, processed to different degrees, and by the lack of mature and spliced tRNA molecules. These results suggest an essential role of MatK for splicing of its own transcript in vivo. Processing of the 5' end of trnK exon 1 was found to proceed efficiently also in the mutant plastids although the two tRNA exons were separated by the 2481 nt intron. Consequently, presence of the intron does not interfere with the formation of mature 5' termini.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
270
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
179-87
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Splicing and intron-internal RNA editing of trnK-matK transcripts in barley plastids: support for MatK as an essential splice factor.
pubmed:affiliation
Humboldt-University, Department of Biology, Berlin, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't