Control of the Bacillus subtilis antiterminator protein GlcT by phosphorylation. Elucidation of the phosphorylation chain leading to inactivation of GlcT.
Bacillus subtilis transports glucose by the phosphotransferase system (PTS). The genes for this system are encoded in the ptsGHI operon, which is induced by glucose and depends on a termination/antitermination mechanism involving a riboswitch and the RNA-binding antitermination protein GlcT. In the absence of glucose, GlcT is inactive, and a terminator is formed in the leader region of the ptsG mRNA. If glucose is present, GlcT can bind to its RNA target and prevent transcription termination. The GlcT protein is composed of three domains, an N-terminal RNA binding domain and two PTS regulation domains, PTS regulation domain (PRD) I and PRD-II. In this work, we demonstrate that GlcT can be phosphorylated by two PTS proteins, HPr and the glucose-specific enzyme II (EIIGlc). HPr-dependent phosphorylation occurs on PRD-II and has a slight stimulatory effect on GlcT activity. In contrast, EIIGlc phosphorylates the PRD-I of GlcT, and this phosphorylation inactivates GlcT. This latter phosphorylation event links the availability of glucose to the expression of the ptsGHI operon via the phosphorylation state of EIIGlc and GlcT. This is the first in vitro demonstration of a direct phosphorylation of an antiterminator of the BglG family by the corresponding PTS permease.
Schmalisch
Matthias H
MH
Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nuremberg, Staudtstrasse 5, D-91058 Erlangen, Germany.
Bachem
Steffi
S
Stülke
Jörg
J
D001412:Bacillus subtilis / Q000737:chemistry*; D001426:Bacterial Proteins / Q000378:metabolism*; D001665:Binding Sites; D008954:Models, Biological; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism; D010766:Phosphorylation; D017434:Protein Structure, Tertiary; D016601:RNA-Binding Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
D001426:Bacterial Proteins; C115000:GlcT protein, Bacillus subtilis; D016601:RNA-Binding Proteins; C442131:ScoC protein, Bacillus subtilis; D014157:Transcription Factors; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C031629:phosphoenolpyruvate-glucose phosphotransferase