pfam18710: ComR_TPR (This model is not part of the current CDD release)
ComR tetratricopeptide
In Gram-positive bacteria, cell-to-cell communication mainly relies on extracellular signaling peptides. ComR is a member of the RNPP family, which positively controls competence for natural DNA transformation in streptococci. It is directly activated by the binding of its associated pheromone XIP. The crystal structure analysis of ComR shows that it contains an N-terminal helix-turn-helix (HTH), DNA binding domain (DBD) and a C-terminal tetratricopeptide repeat (TPR) domain. The TPR domain is composed of 11 alpha-helices forming 5 TPR motifs followed by an additional C-terminal alpha-helix 16 called CAP. The pheromone XIP binding site is found in the TPR region. Biochemical and mutational analysis indicate that, if the interacting XIP is accepted it can then trigger the conformational change of the TPR domain to open the DBD-TPR interface to allow dimer formation that is required to bind DNA.
Jiyao W et al.(2023). "The conserved domain database in 2023.",