title: Mycobacterial toxin MazF-mt6 inhibits translation through cleavage of 23S rRNA at the ribosomal A site.
abstract: The Mycobacterium tuberculosis genome contains an unusually high number of toxin-antitoxin modules, some of which have been suggested to play a role in the establishment and maintenance of latent tuberculosis. Nine of these toxin-antitoxin loci belong to the mazEF family, encoding the intracellular toxin MazF and its antitoxin inhibitor MazE. Nearly every MazF ortholog recognizes a unique three- or five-base RNA sequence and cleaves mRNA. As a result, these toxins selectively target a subset of the transcriptome for degradation and are known as "mRNA interferases." Here we demonstrate that a MazF family member from M. tuberculosis, MazF-mt6, has an additional role--inhibiting translation through targeted cleavage of 23S rRNA in the evolutionarily conserved helix/loop 70. We first determined that MazF-mt6 cleaves mRNA at (5')UU↓CCU(3') sequences. We then discovered that MazF-mt6 also cleaves M. tuberculosis 23S rRNA at a single UUCCU in the ribosomal A site that contacts tRNA and ribosome recycling factor. To gain further mechanistic insight, we demonstrated that MazF-mt6-mediated cleavage of rRNA can inhibit protein synthesis in the absence of mRNA cleavage. Finally, consistent with the position of 23S rRNA cleavage, MazF-mt6 destabilized 50S-30S ribosomal subunit association. Collectively, these results show that MazF toxins do not universally act as mRNA interferases, because MazF-mt6 inhibits protein synthesis by cleaving 23S rRNA in the ribosome active center.
authors: Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School at Rutgers University, Piscataway, NJ 08854, USA.
authors: Jason M
authors: JM
authors: Schifano
authors: Regina
authors: R
authors: Edifor
authors: Jared D
authors: JD
authors: Sharp
authors: Ming
authors: M
authors: Ouyang
authors: Arvind
authors: A
authors: Konkimalla
authors: Robert N
authors: RN
authors: Husson
authors: Nancy A
authors: NA
authors: Woychik
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D009169:Mycobacterium tuberculosis / Q000235:genetics / Q000378:metabolism*; D014176:Protein Biosynthesis / Q000502:physiology; D012329:RNA, Bacterial / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012338:RNA, Ribosomal, 23S / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D054681:Ribosome Subunits, Large, Bacterial / Q000235:genetics / Q000378:metabolism*; D054680:Ribosome Subunits, Small, Bacterial / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012338:RNA, Ribosomal, 23S; D016601:RNA-Binding Proteins
references: Infect Immun. 2008 Feb;76(2):717-25
references: 18070897
references: Mol Cell. 2003 Oct;12(4):913-23
references: 14580342
references: Mol Cell. 2003 Jan;11(1):91-102
references: 12535524
references: Mol Microbiol. 2002 Feb;43(3):717-31
references: 11929527
references: Annu Rev Microbiol. 2010;64:357-72
references: 20528688
references: FEMS Microbiol Rev. 2012 May;36(3):514-32
references: 22320122
references: RNA. 2011 Feb;17(2):338-45
references: 21135037
references: mBio. 2011 Jun 14;2(3):e00100-11
references: 21673191
references: J Biol Chem. 2004 May 14;279(20):20678-84
references: 15024022
references: Res Microbiol. 2006 Jun;157(5):445-55
references: 16483748
references: Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):6059-63
references: 8650219
references: J Bacteriol. 2010 Mar;192(5):1279-91
references: 20061486
references: Science. 2005 Sep 2;309(5740):1508-14
references: 16141058
references: EMBO J. 2005 Jan 26;24(2):251-60
references: 15616575
references: J Bacteriol. 2009 May;191(10):3248-55
references: 19251861
references: Arch Microbiol. 2005 Nov;184(3):152-7
references: 16175359
references: PLoS One. 2008 Jan 30;3(1):e1502
references: 18231589
references: BMC Evol Biol. 2006 Nov 15;6:95
references: 17105670
references: Mol Microbiol. 2003 Nov;50(3):1031-42
references: 14617159
references: Cell. 2005 Mar 11;120(5):599-611
references: 15766524
references: J Mol Biol. 1999 Jan 8;285(1):107-13
references: 9878392
references: FEBS J. 2005 Feb;272(3):685-95
references: 15670150
references: J Bacteriol. 2009 Mar;191(5):1618-30
references: 19114484
references: Mol Microbiol. 2011 Dec;82(5):1260-76
references: 22014150
references: PLoS Genet. 2009 Dec;5(12):e1000767
references: 20011113
references: J Biol Chem. 2005 Feb 4;280(5):3143-50
references: 15537630
references: Nucleic Acids Res. 1995 May 11;23(9):1512-7
references: 7784204
references: Biochem Biophys Res Commun. 2010 Sep 24;400(3):293-8
references: 20705052
references: Cell. 2011 Sep 30;147(1):147-57
references: 21944167
references: Genome Res. 2004 Jun;14(6):1188-90
references: 15173120
references: Eur J Biochem. 1970 Dec;17(3):433-40
references: 4924194
references: Mol Microbiol. 2002 Jul;45(2):501-10
references: 12123459
references: Microbiology (Reading). 2002 Oct;148(Pt 10):3129-3138
references: 12368446
references: J Bacteriol. 2009 Apr;191(7):2051-9
references: 19168622
references: J Biol Chem. 2006 Jul 7;281(27):18638-43
references: 16611633
references: J Bacteriol. 2009 Oct;191(19):6157-66
references: 19633073
references: Science. 2000 Aug 11;289(5481):905-20
references: 10937989
references: Nat Commun. 2012 Jan 03;3:607
references: 22215082
references: J Mol Biol. 2003 Sep 26;332(4):809-19
references: 12972253
references: Nucleic Acids Res. 2005 Feb 17;33(3):966-76
references: 15718296
references: J Bacteriol. 2012 Jul;194(13):3464-74
references: 22544268
references: Mol Microbiol. 2008 Aug;69(3):559-69
references: 18485066
references: Nat Chem Biol. 2011 Jun;7(6):359-66
references: 21516113
references: Eur J Biochem. 1973 Aug 1;37(1):12-20
references: 4580882
references: Microbiology (Reading). 2009 Apr;155(Pt 4):1093-1102
references: 19332811
references: Proc Natl Acad Sci U S A. 2004 Jun 15;101(24):8900-5
references: 15178758
references: Mol Cell. 2005 Apr 15;18(2):253-61
references: 15837428
references: Science. 2001 May 4;292(5518):883-96
references: 11283358