This domain is found at the N-terminal region of Cyclic-di-AMP phosphodiesterase GdpP from Geobacillus thermodenitrificans. GdpP is a stress signaling protein with phosphodiesterase activity against cyclic-di-AMP (c-di-AMP). This protein contains three protein domains in addition to the two N-terminal transmembrane helices: a Per-ARNT-Sim (PAS) domain (this entry), a GGDEF domain, and a DHH/DHHA1 domain (Pfam:PF01368 and Pfam:PF02272). This domain adopts the typical alpha-beta-PAS domain fold formed by several short and distorted alpha-helices and one five-stranded antiparallel beta- sheet. Noticeably, three of the strands and one of the helices are shorter than those found in other typical PAS domains [1].

1: Solution structure of the PAS domain of a thermophilic YybT protein homolog reveals a potential ligand-binding site. Tan E, Rao F, Pasunooti S, Pham TH, Soehano I, Turner MS, Liew CW, Lescar J, Pervushin K, Liang ZX; J Biol Chem. 2013;288:11949-11959. PMID:23504327