Members of this family are long (~850 residue) bacterial proteins from the alpha Proteobacteria. Each has 2-3 predicted transmembrane helices near the N-terminus and a long C-terminal region that includes stretches of Gln/Gly-rich low complexity sequence, predicted by TMHMM to be outside the membrane. In Bradyrhizobium japonicum, two tandem reading frames are together homologous the single members found in other species; the cutoffs scores are set low enough that the longer scores above the trusted cutoff and the shorter above the noise cutoff for this model.
Jiyao W et al.(2023). "The conserved domain database in 2023.",