Transcriptional regulation is process crucial to metabolic control and development in all organisms. In bacteria, gene expression is controlled at the transcriptional level, through interactions between DNA operators and regulatory proteins. Recent studies of bacterial genomes led to the discovery of a large number of putative transcriptional regulators, with the assignment of new families and subfamilies. One of these is the SorC family, which includes proteins that control the expression of genes and operons involved in the metabolism of sugar substrates. SorC family repressors contain conserved helix-turn-helix domain DNA-binding (DBD) at their N-terminus and an effector-binding domain (EBD) at their C-terminus. The DBD recognizes palindromic operator sequence usually located downstream of the promotor. The C-terminal effector domain has a phosposugar binding function and also plays role in oligomerization.
We structurally characterized two members of SorC family, CggR and DeoR from Bacillus subtilis.
We determined structures using X-ray crystallography and cryo-electron microscopy to follow the DNA binding and allosteric changes induced by effector binding. Structural studies of these two representatives will provide information necessary for understanding the mechanisms of gene regulation by SorC repressors.