Effects of Escherichia coli Nus A protein on transcription termination in vitro are not increased or decreased by DNA sequences sufficient for antitermination in vivo.
The ability of Escherichia coli Nus A protein to recognize specific DNA or RNA sequences in vitro was tested by using transcription templates containing a variety of promoters, transcription terminators, and antitermination-conferring regions. We conclude that the effects of Nus A on termination are not qualitatively or quantitatively altered by sequences present in promoters, Rho-dependent terminators, or antitermination-conferring regions. Nus A was also shown to increase termination at the rrnC Rho-independent T1 terminator by a mechanism that is independent of the promoter or sequences involved in antitermination. Altogether, these observations argue against a direct Nus A-nucleic acid interaction affecting termination in vitro. Together with the results described in the accompanying paper [Sigmund, C. D., & Morgan, E. A. (1988) Biochemistry (preceding paper in this issue)], these results suggest that the effects of Nus A on termination in vitro may not be related to the in vivo functions of Nus A.
Sigmund
C D
CD
Department of Experimental Biology, Roswell Park Memorial Institute, Buffalo, New York 14263.
Morgan
E A
EA
D001426:Bacterial Proteins / Q000502:physiology*; D010582:Bacteriophage lambda / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics*; D005809:Genes, Regulator; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid; D013728:Terminator Regions, Genetic; D014157:Transcription Factors / Q000502:physiology*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D014157:Transcription Factors