Abstract
The bgl system represents a family of sensory systems composed of membrane-bound sugar-sensors and transcriptional antiterminators, which regulate expression of genes involved in sugar utilization in response to the presence of the corresponding sugar in the growth medium. The BglF sensor catalyzes different activities depending on its stimulation state: in its non-stimulated state, it phosphorylates the BglG transcriptional regulator, thus inactivating it; in the presence of the stimulating sugar, it transports the sugar and phosphorylates it and also activates BglG by dephosphorylation, leading to bgl operon expression. The sugar stimulates BglF by inducing a change in its membrane topology. BglG exists in several conformations: a dimer, which is active, and compact and non-compact monomers, which are inactive. BglF modulates the transition of BglG from one conformation to another, depending on sugar availability. The two Bgl proteins form a pre-complex at the membrane that dissociates upon stimulation, enabling BglG to exert its effect on transcription.
| Original language | English |
|---|---|
| Pages (from-to) | 127-134 |
| Number of pages | 8 |
| Journal | Current Opinion in Microbiology |
| Volume | 8 |
| Issue number | 2 |
| DOIs | |
| State | Published - Apr 2005 |
Bibliographical note
Funding Information:I thank Anat Nussbaum-Shochat for artwork. I thank Andrew Wright and Liat Fux for critical reading of the manuscript. I appreciate valuable discussions with members of my laboratory. Research in the author's laboratory has been supported by the Israel Science Foundation founded by the Israel Academy of Sciences and Humanities.