Protein Family Models

The PAS fold corresponds to the structural domain that has previously been defined as PAS and PAC motifs [4]. The PAS fold appears in archaea, eubacteria and eukarya. This domain is associated to signalling systems and works as a signal sensor domain. It recognises differently substituted aromatic hydrocarbons, oxygen, different dodecanoic acids, autoinducers, 3,5-dimethyl-pyrazin-2-ol and N-alanyl-aminoacetone (Matilla et. al., FEMS Microbiology Reviews, fuab043, 45, 2021, 1. https://doi.org/10.1093/femsre/fuab043). [1]. 9301332. PAS domain S-boxes in archaea, bacteria and sensors for oxygen and redox. Zhulin IB, Taylor BL, Dixon R;. Trends Biochem Sci 1997;22:331-333. [2]. 7756254. 1.4 A structure of photoactive yellow protein, a cytosolic photoreceptor: unusual fold, active site, and chromophore. Borgstahl GE, Williams DR, Getzoff ED;. Biochemistry 1995;34:6278-6287. [3]. 9382818. PAS: a multifunctional domain family comes to light. Ponting CP, Aravind L;. Curr Biol 1997;7:674-677. [4]. 15009198. The PAS fold: a redefination of the PAS domain based upon structural prediction. Hefti MH, Francoijs KJ, de Vries SC, Dixon R, Vervoort J;. Eur J Biochem 2004;271:1198-1208. (from Pfam)

Date:

2024-10-16

Date:

2024-08-14

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 controls the expression of genes with diverse biological functions including metabolism, stress response, and virulence; contains an N-terminal PAS domain which functions as a signal sensor

Date:

2017-02-24