Structure of the Trypanosoma brucei p22 protein, a cytochrome oxidase subunit II-specific RNA-editing accessory factor.
Kinetoplastid RNA (k-RNA) editing is a complex process in the mitochondria of kinetoplastid protozoa, including Trypanosoma brucei, that involves the guide RNA-directed insertion and deletion of uridines from precursor-mRNAs to produce mature, translatable mRNAs. k-RNA editing is performed by multiprotein complexes called editosomes. Additional non-editosome components termed k-RNA-editing accessory factors affect the extent of editing of specific RNAs or classes of RNAs. The T. brucei p22 protein was identified as one such accessory factor. Here we show that p22 contributes to cell growth in the procyclic form of T. brucei and functions as a cytochrome oxidase subunit II-specific k-RNA-editing accessory factor. To gain insight into its functions, we solved the crystal structure of the T. brucei p22 protein to 2.0-A resolution. The p22 structure consists of a six-stranded, antiparallel beta-sheet flanked by five alpha-helices. Three p22 subunits combine to form a tight trimer that is primarily stabilized by interactions between helical residues. One side of the trimer is strikingly acidic, while the opposite face is more neutral. Database searches show p22 is structurally similar to human p32, which has a number of functions, including regulation of RNA splicing. p32 interacts with a number of target proteins via its alpha1 N-terminal helix, which is among the most conserved regions between p22 and p32. Co-immunoprecipitation studies showed that p22 interacts with the editosome and the k-RNA accessory protein, TbRGG2, and alpha1 of p22 was shown to be important for the p22-TbRGG2 interaction. Thus, these combined studies suggest that p22 mediates its role in k-RNA editing by acting as an adaptor protein.
Sprehe
Mareen
M
Department of Biochemistry and Molecular Biology, University of Texas MD Anderson Cancer Center, Houston, Texas 77030, USA.
Fisk
John C
JC
McEvoy
Sarah M
SM
Read
Laurie K
LK
Schumacher
Maria A
MA
D002352:Carrier Proteins / Q000378:metabolism*; D018105:DNA, Kinetoplast / Q000378:metabolism; D003576:Electron Transport Complex IV / Q000737:chemistry*; D006801:Humans; D008928:Mitochondria / Q000378:metabolism; D009154:Mutation; D011487:Protein Conformation; D012313:RNA / Q000737:chemistry*; D017393:RNA Editing; D034622:RNA Interference; D011994:Recombinant Proteins / Q000737:chemistry; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014346:Trypanosoma brucei brucei / Q000378:metabolism*
D002352:Carrier Proteins; D018105:DNA, Kinetoplast; D011994:Recombinant Proteins; D012313:RNA; D003576:Electron Transport Complex IV
Acta Crystallogr D Biol Crystallogr. 1994 Sep 1;50(Pt 5):760-3
15299374
Cell. 2006 Aug 25;126(4):701-11
16923390
J Biol Chem. 1996 May 31;271(22):13040-7
8662673
Proc Natl Acad Sci U S A. 1996 Sep 17;93(19):10423-7
8816816
Acta Crystallogr D Biol Crystallogr. 2004 Dec;60(Pt 12 Pt 1):2126-32
15572765
J Gen Virol. 1998 Jul;79 ( Pt 7):1677-85
9680131
Trends Parasitol. 2006 Apr;22(4):168-74
16504583
RNA. 2005 Jan;11(1):29-37
15574518
FEBS Lett. 1994 Jun 13;346(2-3):225-8
7516896
RNA. 2003 Apr;9(4):484-92
12649499
Nucleic Acids Res. 1993 Sep 11;21(18):4313-20
8414987
Eur J Biochem. 1996 Sep 15;240(3):721-31
8856076
Methods Enzymol. 1997;276:523-30
9048379
J Virol. 2004 Nov;78(22):12416-27
15507628
RNA. 2009 Feb;15(2):277-86
19096045
J Biol Chem. 1997 Sep 26;272(39):24363-70
9305894
J Synchrotron Radiat. 2004 Jan 1;11(Pt 1):49-52
14646132
J Biol Chem. 1998 Aug 21;273(34):21825-33
9705321
J Am Soc Mass Spectrom. 2003 Jul;14(7):728-35
12837594
Cell. 2002 Mar 8;108(5):637-48
11893335
RNA. 2006 Aug;12(8):1545-55
16775306
J Virol. 1995 May;69(5):3007-16
7707527
Infect Immun. 2000 Apr;68(4):2061-8
10722602
Acta Crystallogr D Biol Crystallogr. 1998 Sep 1;54(Pt 5):905-21
9757107
J Biol Chem. 2004 Jun 4;279(23):24123-30
15060068
J Virol. 2000 Dec;74(23):11322-8
11070032
Proc Natl Acad Sci U S A. 1988 Jan;85(2):539-43
2448777
Immunol Rev. 2001 Apr;180:65-77
11414365
RNA. 2008 May;14(5):970-80
18369185
Mol Biochem Parasitol. 2002 Nov-Dec;125(1-2):211-6
12467990
Exp Cell Res. 2005 Oct 1;309(2):250-63
16039650
RNA. 2003 Apr;9(4):457-68
12649497
Mol Cell Biol. 1996 Apr;16(4):1410-8
8657114
J Virol. 1995 May;69(5):3017-23
7707528
J Virol. 2006 Apr;80(7):3189-204
16537587
EMBO J. 1999 Feb 15;18(4):1014-24
10022843
Mol Cell Biol. 1988 Mar;8(3):1259-65
2452974
Proc Natl Acad Sci U S A. 2005 Nov 15;102(46):16614-9
16269544
Mol Microbiol. 2004 Aug;53(3):717-24
15255886
Yeast. 1998 Mar 15;14(4):303-10
9559539
Mol Biochem Parasitol. 1999 Mar 15;99(1):89-101
10215027
Nucleic Acids Res. 2001 Dec 15;29(24):5216-25
11812855
Proc Natl Acad Sci U S A. 2004 Mar 30;101(13):4333-4
15070715
RNA. 2009 Jul;15(7):1338-44
19447916
J Biol Chem. 2005 Sep 30;280(39):33357-67
15975922
Protist. 2001 Dec;152(4):255-62
11822657
Appl Environ Microbiol. 1999 Dec;65(12):5222-8
10583968
Mol Cell. 2008 Oct 24;32(2):198-209
18951088
J Biol Chem. 1996 Apr 5;271(14):8365-72
8626534
Cell. 1986 Sep 12;46(6):819-26
3019552
Proc Natl Acad Sci U S A. 1996 Aug 6;93(16):8552-7
8710908
J Biol Chem. 2002 Feb 15;277(7):5247-55
11698413
EMBO J. 2000 Apr 3;19(7):1458-66
10747014
J Virol. 2005 Aug;79(16):10807-20
16051872
J Virol. 2002 Nov;76(22):11612-22
12388722
Mol Microbiol. 2002 Aug;45(3):591-6
12139607
J Cell Sci. 2005 Jan 15;118(Pt 2):283-90
15654017
J Virol. 1994 Jun;68(6):3850-6
8189522
Cell. 1988 May 6;53(3):401-11
2452696
J Biol Chem. 1990 Jul 5;265(19):11368-76
1694178
Mol Cell Biol. 2008 Jan;28(1):122-30
17954557
Cell. 1990 Jan 26;60(2):189-98
1688737
RNA. 2003 Mar;9(3):265-76
12591999
RNA. 2004 Feb;10(2):159-70
14730014
Biochem Biophys Res Commun. 1996 Jan 5;218(1):260-6
8573143
J Exp Med. 1994 Jun 1;179(6):1809-21
8195709
Science. 1994 Oct 7;266(5182):114-7
7524149
J Biol Chem. 2004 Jan 16;279(3):1607-14
14583623
Nucleic Acids Res. 1997 Jun 15;25(12):2311-8
9171080
J Biol Chem. 1999 Apr 23;274(17):12067-74
10207031
J Biol Chem. 2007 Mar 9;282(10):7181-90
17229732
Curr Genet. 2005 Nov;48(5):277-99
16215758
J Biol Chem. 1996 Apr 26;271(17):10066-72
8626563
Cell. 1987 May 8;49(3):337-45
3568129
RNA. 2008 Jun;14(6):1069-80
18441045
Mol Cell Proteomics. 2008 Mar;7(3):534-45
18073385
Mol Cell Biol. 2001 Oct;21(20):6833-40
11564867
Science. 2000 Mar 3;287(5458):1639-40
10698736
Mol Cell Biol. 2001 Jan;21(2):380-9
11134327
Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3572-7
10097078
Proteins. 2008 May 15;71(3):1563-71
18300248
Cell Death Differ. 2004 Jul;11(7):771-81
15031724
Acta Crystallogr D Biol Crystallogr. 1999 Apr;55(Pt 4):849-61
10089316
J Cell Biol. 2000 Feb 21;148(4):653-63
10684248
Trends Biochem Sci. 2005 Feb;30(2):97-105
15691655
Genes Dev. 1990 Jul;4(7):1158-71
2145194
Virology. 1997 Sep 15;236(1):18-29
9299613
J Biol Chem. 1996 Jan 26;271(4):2206-12
8567680
J Clin Invest. 2000 Nov;106(10):1239-49
11086025
Nucleic Acids Res. 2004 Jul 08;32(12):3632-41
15243141
Cancer Cell. 2008 Jun;13(6):542-53
18538737
J Biol Chem. 2008 Aug 22;283(34):23016-25
18583347