Splicing and evolution of an unusually small group I intron.
Introns are common in the rRNA gene loci of fungal genomes, but biochemical studies to investigate splicing are rare. Here, self-splicing of a very small (67 nucleotide) group I intron is demonstrated. The PaSSU intron (located within the rRNA small subunit gene of Phialophora americana) splices in vitro under group I intron conditions. Most group I ribozymes contain pairing regions P1-P10, with a conserved G.U pair at the 5' splice site, and a G at the 3' intron border. The PaSSU intron contains only P1, P7, and P10. While it contains the G.U pair at the 5' splice, a U is found at the 3' end of the intron instead of a G. Phylogenetic analysis places it within subgroup IC1, whose members are found in the nuclear rRNA genes of fungi. The structural elements are similar to those in the centermost regions of other group I introns. Its size can be explained by a single large deletion that removed P2 through much of P9. Part of the original P9 region has assumed the function of P7. Its small size and genealogy makes it an excellent model to study RNA catalysis and evolution.
Harris
Lorena
L
Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
Rogers
Scott O
SO
D020413:3' Untranslated Regions; D001483:Base Sequence; D002384:Catalysis; D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D019143:Evolution, Molecular; D017353:Gene Deletion; D007438:Introns; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010676:Phialophora / Q000378:metabolism; D010802:Phylogeny; D012326:RNA Splicing; D016337:RNA, Catalytic / Q000737:chemistry
D020413:3' Untranslated Regions; D017931:DNA Primers; D016337:RNA, Catalytic; D004247:DNA
Mol Biol Evol. 2000 May;17(5):751-6
10779535
FEMS Microbiol Rev. 1999 Jun;23(3):257-75
10371033
Curr Genet. 1996 Mar;29(4):377-87
8598059
Annu Rev Biochem. 1990;59:543-68
2197983
Nat Struct Mol Biol. 2005 Jan;12(1):82-9
15580277
Mol Cell. 2004 Nov 5;16(3):351-62
15525509
Mol Cell Biol. 1989 Dec;9(12):5480-3
2685567
Cell. 1994 Feb 25;76(4):725-34
8124711
J Mol Biol. 1990 Dec 5;216(3):585-610
2258934
Nucleic Acids Res. 2005 Aug 12;33(14):4602-11
16100381
J Mol Evol. 2007 Feb;64(2):181-95
17200806
Nature. 1989 Mar 16;338(6212):217-24
2466202
Chem Biol. 1996 Dec;3(12):993-1009
9000010
Mol Biol Evol. 2000 Dec;17(12):1971-84
11110913
Gene. 1988 Dec 20;73(2):259-71
3072259
Nat Struct Biol. 2000 Nov;7(11):1032-5
11062558
J Mol Evol. 2005 Apr;60(4):434-46
15883879
J Mol Biol. 1997 Nov 7;273(4):782-8
9367771
Proc Natl Acad Sci U S A. 1989 Oct;86(19):7402-6
2678103
Curr Genet. 1993;23(4):338-42
8467532
Nature. 2002 Jul 11;418(6894):222-8
12110898
Mol Biol Evol. 1995 Mar;12(2):208-18
7700150
Nucleic Acids Res. 1994 Feb 25;22(4):592-6
8127708
Nucleic Acids Res. 2003 Apr 1;31(7):1921-34
12655009
Nucleic Acids Res. 1991 Aug 25;19(16):4429-36
1886767
Curr Genet. 1996 May;29(6):582-6
8662198
J Mol Biol. 1994 Feb 11;236(1):49-63
8107125
RNA. 2004 Dec;10(12):1867-87
15547134
RNA. 2005 Jan;11(1):59-69
15574515