Clostridium difficile IStron CdISt1: discovery of a variant encoding two complete transposase-like proteins.
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.
Hasselmayer
Oliver
O
Institute of Medical Microbiology and Hygiene, Johannes Gutenberg University of Mainz, D-55101 Mainz, Germany. hasselm@mail.uni-mainz.de
Braun
Veit
V
Nitsche
Claudia
C
Moos
Michael
M
Rupnik
Maja
M
von Eichel-Streiber
Christoph
C
D016360:Clostridioides difficile / Q000201:enzymology / Q000235:genetics*; D004251:DNA Transposable Elements; D005798:Genes, Bacterial; D007438:Introns; D008969:Molecular Sequence Data; D019895:Transposases / Q000235:genetics*
D004251:DNA Transposable Elements; D019895:Transposases