title: Clostridium difficile IStron CdISt1: discovery of a variant encoding two complete transposase-like proteins.
abstract: Screening a Clostridium difficile strain collection for the chimeric element CdISt1, we identified two additional variants, designated CdISt1-0 and CdISt1-III. In in vitro assays, we could prove the self-splicing ribozyme activity of these variants. Structural comparison of all known CdISt1 variants led us to define four types of IStrons that we designated CdISt1-0 through CdISt1-III. Since CdISt1-0 encodes two complete transposase-like proteins (TlpA and TlpB), we suggest that it represents the original genetic element, hypothesized before to have originated by fusion of a group I intron and an insertion sequence element.
authors.affiliation: Institute of Medical Microbiology and Hygiene, Johannes Gutenberg University of Mainz, D-55101 Mainz, Germany. hasselm@mail.uni-mainz.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Hasselmayer
authors.forename: Veit
authors.initials: V
authors.lastname: Braun
authors.forename: Claudia
authors.initials: C
authors.lastname: Nitsche
authors.forename: Michael
authors.initials: M
authors.lastname: Moos
authors.forename: Maja
authors.initials: M
authors.lastname: Rupnik
authors.forename: Christoph
authors.initials: C
authors.lastname: von Eichel-Streiber
mesh_terms: D016360:Clostridioides difficile / Q000201:enzymology / Q000235:genetics*; D004251:DNA Transposable Elements; D005798:Genes, Bacterial; D007438:Introns; D008969:Molecular Sequence Data; D019895:Transposases / Q000235:genetics*
chemical_list: D004251:DNA Transposable Elements; D019895:Transposases