This domain is predominantly found at the C-terminal end of proteins from cyanobacteria and plants, including Biogenesis factor required for ATP synthase 1 (BFA1, Swiss:F4J1U2) from Arabidopsis thaliana. BFA1 promotes the assembly of the CF1 subcomplex of the chloroplast ATP synthase by specifically interacting with the gamma and beta subunits. This domain consists of ten beta-sheets and one alpha- helix forming a typical beta-barrel, which locates perpendicularly to Pfam:PF12204 [1].

1: Nucleus-Encoded Protein BFA1 Promotes Efficient Assembly of the Chloroplast ATP Synthase Coupling Factor 1. Zhang L, Pu H, Duan Z, Li Y, Liu B, Zhang Q, Li W, Rochaix JD, Liu L, Peng L; Plant Cell. 2018;30:1770-1788. PMID:30012777