The identification of rRNA maturation sites in the microsporidian Encephalitozoon cuniculi argues against the full excision of presumed ITS1 sequence.
In Encephalitozoon cuniculi like in other microsporidia, the primary transcript for SSU and LSU rRNAs includes only one internal transcribed spacer (ITS1) which separates SSU rRNA from the 5.8S region associated with LSU rRNA. The extraction of total RNA from E. cuniculi-infected MRC5 cells using a hot phenol/chloroform procedure enabled us to perform primer extension and S1 nuclease protection experiments in the aim of identifying rRNA maturation sites. Our data support a simple processing (four cleavage sites) with elimination of only nine nucleotides between SSU and LSU rRNA regions. Most of the presumed ITS1 sequence characterized by strain-dependent polymorphism therefore remains linked to SSU rRNA 3' end. A new secondary structure for the sixth domain of E. cuniculi LSU rRNA is proposed following the identification of its 3' terminus.
Peyretaillade
E
E
Parasitologie Moléculaire et Cellulaire, LBP, UMR CNRS 6023, Université Blaise Pascal, Aubière, France.
Peyret
P
P
Metenier
G
G
Vivares
C P
CP
Prensier
G
G
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004285:Dogs; D009670:Encephalitozoon cuniculi / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012335:RNA, Ribosomal / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015719:Single-Strand Specific DNA and RNA Endonucleases / Q000378:metabolism
D017931:DNA Primers; D021903:DNA, Ribosomal Spacer; D012335:RNA, Ribosomal; D015719:Single-Strand Specific DNA and RNA Endonucleases