This entry represents the N-terminal domain of XylR, an atypical AraC protein. This D-xylose-binding domain contains a periplasmic-binding protein (PBP) fold, similar to LacI/GalR transcription regulators, and mediates dimerization [1].
Bacterial regulatory helix-turn-helix proteins, AraC family
In the absence of arabinose, the N-terminal arm of AraC binds to the DNA binding domain (Pfam:PF00165) and helps to hold the two DNA binding domains in a relative orientation that favours DNA looping. In the presence of arabinose, the arms bind ove ...
In the absence of arabinose, the N-terminal arm of AraC binds to the DNA binding domain (Pfam:PF00165) and helps to hold the two DNA binding domains in a relative orientation that favours DNA looping. In the presence of arabinose, the arms bind over the arabinose on the dimerisation domain, thus freeing the DNA-binding domains. The freed DNA-binding domains are then able to assume a conformation suitable for binding to the adjacent DNA sites that are utilised when AraC activates transcription, and hence AraC ceases looping the DNA when arabinose is added [1-2].
This domain is found in a variety of transcriptional regulatory proteins. It is related to bacterial periplasmic binding proteins, although this domain is unlikely to be found in the periplasm. This domain acts as a sensor binding small molecule liga ...
This domain is found in a variety of transcriptional regulatory proteins. It is related to bacterial periplasmic binding proteins, although this domain is unlikely to be found in the periplasm. This domain acts as a sensor binding small molecule ligands that the DNA-binding domain responds to. This domain recognises Sugars, sugar phosphates, sugar acids and purines (Matilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043).
