PocR, a ligand binding domain, has a novel variant of the PAS-like Fold. Evidence suggests that it binds small hydrocarbon derivatives such as 1,3-propanediol [1]. In (Natural history of sensor domains in bacterial signaling systems by Aravind L, LM Iyer, Anantharaman V, from 'Sensory Mechanisms in Bacteria: Molecular Aspects of Signal Recognition.' Caister Academic Press. 2010) - see (http://de.scribd.com/doc/28576661/Bacterial-Signaling-Chapter)

1: MEDS and PocR are novel domains with a predicted role in sensing simple hydrocarbon derivatives in prokaryotic signal transduction systems. Anantharaman V, Aravind L; Bioinformatics. 2005;21:2805-2811. PMID:15814558