This protein family is found in fungi and bacteria, including the alpha subunit of an haem-dependent oxidative N-demethylase (HODM) from Pseudomonas mendocina. This protein, catalytically active, is responsible for haem, oxygen and NADPH-dependent dimethylamine (DMA) binding. It shows structural similarity to the to the Aer2 PAS domain, but lacks the core PAS-domain alpha-helix that forms the Aer2 haem pocket, and displays extended beta-strands and a longer loop [1].

1: An oxidative N-demethylase reveals PAS transition from ubiquitous sensor to enzyme. Ortmayer M, Lafite P, Menon BR, Tralau T, Fisher K, Denkhaus L, Scrutton NS, Rigby SE, Munro AW, Hay S, Leys D; Nature. 2016;539:593-597. PMID:27851736