Specific interaction of the RNA-binding domain of the Bacillus subtilis transcriptional antiterminator GlcT with its RNA target, RAT

Expression of the Bacillus subtilis ptsGHI operon is controlled by transcri ptional antitermination mediated by the antiterminator protein GlcT. The an titerminator is inactivated in the absence of glucose, presumably by phosph orylation. A conditional terminator in the ptsG mRNA leader region has been identified. Mutations in this terminator resulted in constitutive expressi on of the operon. The terminator is overlapped by an inverted repeat (calle d ribonucleic-antiterminator, RAT) which is thought to form a stem-loop str ucture upon binding of the antiterminator protein GlcT. The N-terminal 60 a mino acid residues of GlcT are able to bind to the RAT and prevent transcri ptional termination in vivo. Sequence specific interaction between the RNA- binding domain and the RAT was demonstrated by surface plasmon resonance an alysis. Mutations affecting the RNA-binding domain were isolated and will b e discussed with respect to their consequences for dimerization and RNA bin ding. (C) 1999 Academic Press.