An archaeal homing endonuclease I-PogI cleaves at the insertion site of the neighboring intron, which has no nested open reading frame

FEBS Lett. 2003 Jun 5;544(1-3):165-70. doi: 10.1016/s0014-5793(03)00497-6.

Abstract

Homing endonucleases (HEs) of the LAGLIDADG family cleave intron/inteinless cognate DNA at, or near, the insertion site (IS) of their own intron/intein. Here, we describe a notable exception to this rule. Two introns, Pog.S1205 (length 32 bp) and Pog.S1213 (664 bp), whose ISs are 8 bp apart, exist within the 16S rRNA gene of the archaeon Pyrobaculum oguniense. Pog.S1213 harbors a nested open reading frame (ORF) encoding a 22 kDa monomeric protein, I-PogI, which contains two LAGLIDADG motifs and has optimal DNA cleavage activity at 90 degrees C. Intriguingly, I-PogI cleaves the Pog.S1205-less substrate DNA in the presence or absence of Pog.S1213. The cleavage site (CS) of I-PogI does not coincide with the IS of Pog.S1213 but with that of Pog.S1205. Thus, I-PogI activity both promotes the homing of its own intron, Pog.S1213, and guarantees co-conversion of the ORF-less intron Pog.S1205.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Archaea / genetics*
  • Base Sequence
  • Catalysis
  • DNA, Ribosomal / metabolism
  • Electrophoresis, Polyacrylamide Gel
  • Endonucleases / pharmacology*
  • Exons
  • Introns
  • Molecular Sequence Data
  • Open Reading Frames
  • Phylogeny
  • Plasmids / metabolism
  • Protein Binding
  • RNA, Ribosomal, 16S / metabolism
  • Sequence Homology, Amino Acid
  • Temperature

Substances

  • DNA, Ribosomal
  • RNA, Ribosomal, 16S
  • Endonucleases
  • endonuclease I-PogI

Associated data

  • GENBANK/AB087402