title: The complete sequence of a brown algal mitochondrial genome, the ectocarpale Pylaiella littoralis (L.) Kjellm.
abstract: We describe here the complete sequence (58,507 bp) of the mitochondrial genome of the brown alga Pylaiella littoralis (Ectocarpales). This molecule displays an AT content of 62.0% and contains seventy-nine genes, most of them (73) encoded on one strand. They include the usual mitochondrial set of protist genes and a number of rarer genes. Among these, several ribosomal protein genes and the rn5 were identified. Twenty-four tRNA genes are present in this genome, insufficient to decode all genes. The other conspicuous features of this molecule are: a large (3018 nucleotides) in-frame insertion of unknown function in the cox2 gene; the presence of two different lineages of group II introns, including complete reverse transcriptase-like genes, one in the cox1 and the other in the rnl gene; the concomitant occurrence of a T7-like RNA polymerase and of several well-conserved alpha-proteobacterial-type promoters; and a small nad11 gene, coding for the first domain only of this NADH dehydrogenase subunit. Altogether, the mitochondrial genome of P. littoralis exhibits both alpha-proteobacterial characteristics and evidences of the independent integration of several exogenous DNA fragments.
authors.affiliation: UMR 1931, CNRS and Laboratoires Goëmar, Station Biologique de Roscoff, BP 74, 29682 Roscoff Cedex, France.
authors.forename: M P
authors.initials: MP
authors.lastname: Oudot-Le Secq
authors.forename: J M
authors.initials: JM
authors.lastname: Fontaine
authors.forename: S
authors.initials: S
authors.lastname: Rousvoal
authors.forename: B
authors.initials: B
authors.lastname: Kloareg
authors.forename: S
authors.initials: S
authors.lastname: Loiseaux-De Goër
mesh_terms: D020418:Algal Proteins / Q000235:genetics; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics; D008969:Molecular Sequence Data; D000459:Phaeophyceae / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D020418:Algal Proteins; D004272:DNA, Mitochondrial; D012269:Ribosomal Proteins; D012321:DNA-Directed RNA Polymerases