Protein Family Models

Date:

2024-08-14

This family represents the N-terminus of bacterial ARAC-type transcriptional regulators. In E. coli, these regulate the L-arabinose operon through sensing the presence of arabinose, and when the sugar is present, transmitting this information from the arabinose-binding domains to the protein's DNA-binding domains [1]. This family might represent the N-terminal arm of the protein, which binds to the C-terminal DNA binding domains to hold them in a state where the protein prefers to loop and remain non-activating [2]. All family members contain the Pfam:PF00165 domain. [1]. 12683999. Mutational analysis of residue roles in AraC function. Ross JJ, Gryczynski U, Schleif R;. J Mol Biol 2003;328:85-93. [2]. 9600837. Arm-domain interactions in AraC. Saviola B, Seabold R, Schleif RF;. J Mol Biol 1998;278:539-548. (from Pfam)

Date:

2024-10-16

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]. [1]. 9600836. Apo-AraC actively seeks to loop. Seabold RR, Schleif RF;. J Mol Biol 1998;278:529-538. [2]. 9600837. Arm-domain interactions in AraC. Saviola B, Seabold R, Schleif RF;. J Mol Biol 1998;278:539-548. (from Pfam)

Date:

2024-10-16

AraC family transcriptional regulator contains a helix-turn-helix DNA-binding motif and controls the expression of genes with diverse biological functions including metabolism, stress response, and virulence

Date:

2022-08-22