ligand-binding domain of TTHA0807, a CcpA regulator, from Thermus thermophilus HB8 and its close homologs
Ligand-binding domain of the uncharacterized transcription regulator TTHA0807 from the extremely thermophilic organism Thermus thermophilus HB8 and close homologs from other bacteria. Although its exact biological function is not known, the TTHA0807 belongs to the catabolite control protein A (CcpA)family of regulatory proteins. The CcpA functions as the major transcriptional regulator of carbon catabolite repression/regulation (CCR), a process in which enzymes necessary for the metabolism of alternative sugars are inhibited in the presence of glucose. In gram-positive bacteria, CCR is controlled by HPr, a phosphoenolpyruvate:sugar phsophotrasnferase system (PTS) and a transcriptional regulator CcpA. Moreover, CcpA can regulate sporulation and antibiotic resistance as well as play a role in virulence development of certain pathogens such as the group A streptococcus. The ligand binding domain of CcpA is a member of the LacI-GalR family of bacterial transcription regulators.