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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2000-12-6
pubmed:abstractText
We identified group IIA introns that contain an open reading frame (ORF) in the mitochondrial cytochrome oxidase subunit I (cox1) genes of yellow algae, a diatom Thalassiosira (Th.) nordenskioeldii CCMP 992 collected from the east coast of USA, and a haptophyte Pavlova (Pa.) lutheri CCMP 1325 collected from Finland. Cognate introns of CCMP 1325 were detected in all Pa. lutheri strains investigated, which were collected from various oceans. In contrast, the intron was absent from closely related species belonging to the same genus Pavlova. This was also the case for the group II intron detected in a diatom Th. nordenskioeldii CCMP 992. The group II intron of CCMP 992 was located at the corresponding site to the group IIA intron found in Pylaiella (synonym, Pilayella) littoralis. The deduced secondary structures of these introns, one of which is from a diatom and the other from a brown alga, were virtually identical. In contrast, the haptophyte group II intron was inserted at a novel locus, and shares no particularly high sequence homology with any intron known to date. The phylogenetic tree based on the intronic ORF domain was not congruent with that based on the cox1 exon. The most prominent property of the intronic ORF tree was that introns located at homologous sites made robust pair clades irrespective of the phylogenetic relationships of the organisms. This suggests that mitochondrial group II introns often invade intronless alleles across the species barrier with site specificity. Homology analysis of the haptophyte intronic ORF suggested that it comprises three domains: reverse transcriptase (RT), RNA maturase (Ma), and H-N-H endonuclease. However, the intronic ORF of the diatom contains the Ma domain but is apparently missing the H-N-H domain, and its RT domain is most probably partly or completely lacking in function.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0378-1119
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
157-67
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:11054545-Amino Acid Sequence, pubmed-meshheading:11054545-Base Sequence, pubmed-meshheading:11054545-Binding Sites, pubmed-meshheading:11054545-DNA, pubmed-meshheading:11054545-DNA, Mitochondrial, pubmed-meshheading:11054545-Diatoms, pubmed-meshheading:11054545-Electron Transport Complex IV, pubmed-meshheading:11054545-Eukaryota, pubmed-meshheading:11054545-Introns, pubmed-meshheading:11054545-Models, Molecular, pubmed-meshheading:11054545-Molecular Sequence Data, pubmed-meshheading:11054545-Nucleic Acid Conformation, pubmed-meshheading:11054545-Open Reading Frames, pubmed-meshheading:11054545-Phylogeny, pubmed-meshheading:11054545-Protein Subunits, pubmed-meshheading:11054545-Sequence Alignment, pubmed-meshheading:11054545-Sequence Analysis, DNA, pubmed-meshheading:11054545-Sequence Homology, Amino Acid
pubmed:year
2000
pubmed:articleTitle
Distribution of cognates of group II introns detected in mitochondrial cox1 genes of a diatom and a haptophyte.
pubmed:affiliation
Department of Biology, Faculty of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, 560-0043, Osaka, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't