title: Discovery of unconventional kinetochores in kinetoplastids.
abstract: The kinetochore is the macromolecular protein complex that directs chromosome segregation in eukaryotes. It has been widely assumed that the core kinetochore consists of proteins that are common to all eukaryotes. However, no conventional kinetochore components have been identified in any kinetoplastid genome, thus challenging this assumption of universality. Here, we report the identification of 19 kinetochore proteins (KKT1-19) in Trypanosoma brucei. The majority is conserved among kinetoplastids, but none of them has detectable homology to conventional kinetochore proteins. These proteins instead have a variety of features not found in conventional kinetochore proteins. We propose that kinetoplastids build kinetochores using a distinct set of proteins. These findings provide important insights into the longstanding problem of the position of the root of the eukaryotic tree of life.
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK; Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK. Electronic address: bungo.akiyoshi@bioch.ox.ac.uk.
authors.forename: Bungo
authors.initials: B
authors.lastname: Akiyoshi
authors.affiliation: Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
authors.forename: Keith
authors.initials: K
authors.lastname: Gull
mesh_terms: D000595:Amino Acid Sequence; D020090:Chromosome Segregation; D018105:DNA, Kinetoplast; D018386:Kinetochores / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D015800:Protozoan Proteins / Q000032:analysis* / Q000737:chemistry; D016415:Sequence Alignment; D014346:Trypanosoma brucei brucei / Q000737:chemistry*
chemical_list: D018105:DNA, Kinetoplast; D015800:Protozoan Proteins