title: Compromised factor-dependent transcription termination in a nusA mutant of Escherichia coli: spectrum of termination efficiencies generated by perturbations of Rho, NusG, NusA, and H-NS family proteins.
abstract: The proteins NusA and NusG, which are essential for the viability of wild-type Escherichia coli, participate in various postinitiation steps of transcription including elongation, antitermination, and termination. NusG is required, along with the essential Rho protein, for factor-dependent transcription termination (also referred to as polarity), but the role of NusA is less clear, with conflicting reports that it both promotes and inhibits the process. In this study, we found that a recessive missense nusA mutant [nusA(R258C)] exhibits a transcription termination-defective (that is, polarity-relieved) phenotype, much like missense mutants in rho or nusG, but is unaffected for either the rate of transcription elongation or antitermination in λ phage. Various combinations of the rho, nusG, and nusA mutations were synthetically lethal, and the lethality was suppressed by expression of the N-terminal half of nucleoid protein H-NS. Our results suggest that NusA function is indeed needed for factor-dependent transcription termination and that an entire spectrum of termination efficiencies can be generated by perturbations of the Rho, NusG, NusA, and H-NS family of proteins, with the corresponding phenotypes extending from polarity through polarity relief to lethality.
authors: Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500 001, India. shankar@cdfd.org.in
authors: Shivalika
authors: S
authors: Saxena
authors: J
authors: J
authors: Gowrishankar
references: Mol Microbiol. 2004 Mar;51(6):1705-17
references: 15009896
references: Biochemistry. 2003 Nov 25;42(46):13429-37
references: 14621988
references: Microbiol Rev. 1989 Mar;53(1):1-24
references: 2540407
references: Cell. 1992 Mar 6;68(5):989-94
references: 1547498
references: EMBO J. 2005 Oct 19;24(20):3576-87
references: 16193062
references: J Bacteriol. 2011 Aug;193(15):3832-41
references: 21602341
references: Proc Natl Acad Sci U S A. 2011 Jan 11;108(2):792-7
references: 21183718
references: Proc Natl Acad Sci U S A. 2000 Jun 6;97(12):6640-5
references: 10829079
references: J Bacteriol. 1996 Aug;178(15):4335-43
references: 8755860
references: J Mol Biol. 2009 Aug 14;391(2):341-58
references: 19500594
references: J Biol Chem. 1985 Jan 10;260(1):574-84
references: 2981220
references: Genetics. 1992 Mar;130(3):411-28
references: 1551568
references: Nature. 2010 Jan 14;463(7278):245-9
references: 20075920
references: Genes Cells. 2002 Aug;7(8):755-68
references: 12167155
references: Science. 2008 May 16;320(5878):935-8
references: 18487194
references: J Bacteriol. 1978 Jun;134(3):1141-56
references: 149110
references: Nature. 1981 Jul 16;292(5820):212-5
references: 6265784
references: J Mol Biol. 2011 Jan 7;405(1):49-64
references: 21040729
references: Mol Microbiol. 2005 Mar;55(5):1315-24
references: 15720542
references: J Bacteriol. 1999 Jan;181(2):359-67
references: 9882646
references: Virology. 1974 Mar;58(1):141-8
references: 4595374
references: Mol Syst Biol. 2006;2:2006.0008
references: 16738554
references: J Mol Biol. 1998 May 1;278(2):307-16
references: 9571053
references: J Biol Chem. 1975 Feb 25;250(4):1556-62
references: 1089661
references: Microbiology (Reading). 2006 Sep;152(Pt 9):2515-2528
references: 16946247
references: Microbiol Mol Biol Rev. 2004 Dec;68(4):796-813
references: 15590784
references: Curr Biol. 2010 Jan 12;20(1):80-5
references: 20036541
references: J Mol Biol. 1986 May 5;189(1):103-11
references: 3023618
references: Nat Rev Microbiol. 2004 May;2(5):391-400
references: 15100692
references: J Mol Biol. 2011 Oct 7;412(5):793-813
references: 21439297
references: Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1453-7
references: 1741399
references: Mol Cell. 2001 Jun;7(6):1177-89
references: 11430821
references: J Mol Biol. 2001 Dec 14;314(5):1087-95
references: 11743725
references: J Microbiol. 2006 Feb;44(1):11-22
references: 16554712
references: J Biol Chem. 1999 Feb 19;274(8):5245-51
references: 9988775
references: J Mol Biol. 2002 May 17;318(5):1175-88
references: 12083510
references: Proc Natl Acad Sci U S A. 1980 Apr;77(4):1991-4
references: 6154941
references: Proc Natl Acad Sci U S A. 1982 Oct;79(20):6171-5
references: 6216477
references: Microbiol Rev. 1995 Dec;59(4):623-45
references: 8531889
references: Biochim Biophys Acta. 2002 Sep 13;1577(2):251-260
references: 12213656
references: Curr Opin Microbiol. 2008 Apr;11(2):113-20
references: 18387844
references: Proc Natl Acad Sci U S A. 2010 Aug 31;107(35):15517-22
references: 20696893
references: Mol Microbiol. 2004 Nov;54(3):598-603
references: 15491353
references: Genes Dev. 1993 Jan;7(1):161-72
references: 8422985
references: Annu Rev Biochem. 1978;47:967-96
references: 354508
references: Science. 2006 May 19;312(5776):1044-6
references: 16645050
references: Nucleic Acids Res. 1994 Jun 25;22(12):2426-7
references: 8036176
references: J Mol Biol. 2010 Sep 3;401(5):708-25
references: 20600118
references: Annu Rev Microbiol. 2008;62:211-33
references: 18729732
references: J Mol Biol. 2007 Aug 24;371(4):855-72
references: 17599352
references: Microbiol Mol Biol Rev. 1998 Sep;62(3):985-1019
references: 9729612
references: Proc Natl Acad Sci U S A. 1994 Aug 2;91(16):7543-7
references: 8052617
references: J Mol Biol. 2003 Sep 5;332(1):31-46
references: 12946345
references: Microbiol Mol Biol Rev. 1998 Sep;62(3):814-984
references: 9729611
references: Mol Microbiol. 2007 Jan;63(1):7-14
references: 17116239
references: Nat Rev Microbiol. 2010 Mar;8(3):185-95
references: 20140026