The reverse-transcriptase-like proteins encoded by group II introns in the mitochondrial genome of the brown alga Pylaiella littoralis belong to two different lineages which apparently coevolved with the group II ribosyme lineages.
The mitochondrial genome of the brown alga Pylaiella littoralis contains two different types of group II introns. They each encode complete complex proteins, i.e., with a reverse transcriptase domain, a maturase or X domain, and an endonuclease or H-N-H/zinc finger domain. To our knowledge, this is the first example of the presence in the same genome of introns belonging to subgroups IIA and IIB which both contain multidomained RT-like proteins. We describe the group IIA introns that interrupt the cox1 gene. The RT-like proteins contained in these introns were compared to those of the LSU rDNA group IIB introns. The phylogenetic relationships of these intron ORFs were investigated and the possible evolution of group II introns is discussed.
Fontaine
J M
JM
Centre d'Etudes d'Océanographie et de Biologie Marine, Station Biologique de Roscoff, CNRS (UPR 9042), UPMC, BP 74, 29682 Roscoff Cedex, France.
Goux
D
D
Kloareg
B
B
Loiseaux-de Goër
S
S
D000595:Amino Acid Sequence; D001483:Base Sequence; D051545:Cyclooxygenase 1; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D019143:Evolution, Molecular; D007438:Introns / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames / Q000235:genetics; D000459:Phaeophyceae / Q000235:genetics*; D010802:Phylogeny; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics*; D012194:RNA-Directed DNA Polymerase / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D004272:DNA, Mitochondrial; D007527:Isoenzymes; D051545:Cyclooxygenase 1; D011451:Prostaglandin-Endoperoxide Synthases; D012194:RNA-Directed DNA Polymerase