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Review
. 2009 Oct;191(20):6193-202.
doi: 10.1128/JB.00675-09. Epub 2009 Aug 7.

Group I introns and inteins: disparate origins but convergent parasitic strategies

Rahul Raghavan  1 , Michael F Minnick
Affiliations
Review

Group I introns and inteins: disparate origins but convergent parasitic strategies

Rahul Raghavan et al. J Bacteriol. 2009 Oct.
No abstract available

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Figures

FIG. 1.
FIG. 1.
(A) Predicted secondary structure of a group I intron (Cbu.L1951) (93). Paired, conserved helices common to group I introns are designated P1 to P10. The 5′- and 3′-terminal intron bases are encircled. The intron sequence is in uppercase; 5′ and 3′ exons are in lowercase and colored red and blue, respectively. P1 and P10 together form the IGS. The site of HE insertion in P8 is indicated in green. (B) Mechanism of group I intron splicing (110). 5′ and 3′ exons are in red and blue, respectively. ΩG, terminal intron guanine. G*, exogenous guanosine. (Step 1) Nucleophilic attack on the 5′ splice site by the 3′-OH of G* in GBS. (Step 2) Nucleophilic attack on the 3′ splice site by the free 3′-OH of the 5′ exon. (Step 3) Free intron and spliced exons.
FIG. 2.
FIG. 2.
(A) Intein modular structure (87, 90). An intein with flanking exteins is shown. The N- and C-terminal splicing domains and the optional HE domain with their conserved motifs are shown. Conserved amino acids Cys or Ser at the 5′ end of the intein, Asn at the 3′ end of the intein, and Cys, Ser, or Thr at the first position on the 3′ extein are also indicated. (B) Intein splicing chemistry (39, 87). N and C exteins are in red and blue, respectively.
FIG. 3.
FIG. 3.
(A) Intein or group I intron homing through HE-mediated DNA double-strand-break repair and recombination. (B) Cycle model of HE gain, degeneration, and loss within host populations (37, 38, 39).
FIG. 4.
FIG. 4.
Convergence of evolutionary paths of group I introns, inteins, and HEs.
See this image and copyright information in PMC

References

    1. Aagaard, C., J. Z. Dalgaard, and R. A. Garrett. 1995. Intercellular mobility and homing of an archaeal rDNA intron confers a selective advantage over intron− cells of Sulfolobus acidocaldarius. Proc. Natl. Acad. Sci. USA 92:12285-12289. - PMC - PubMed
    1. Amitai, G., O. Belenkiy, B. Dassa, A. Shainskaya, and S. Pietrokovski. 2003. Distribution and function of new bacterial intein-like protein domains. Mol. Microbiol. 47:61-73. - PubMed
    1. Amitai, G., B. Dassa, and S. Pietrokovski. 2004. Protein splicing of inteins with atypical glutamine and aspartate C-terminal residues. J. Biol. Chem. 279:3121-3131. - PubMed
    1. Avise, J. C. 2001. Evolving genomic metaphors: a new look at the language of DNA. Science 294:86-87. - PubMed
    1. Ayre, B. G., U. Köhler, H. M. Goodman, and J. Haseloff. 1999. Design of highly specific cytotoxins by using trans-splicing ribozymes. Proc. Natl. Acad. Sci. USA 96:3507-3512. - PMC - PubMed

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