InterPro domain: IPR022552

This entry represents proteins annotated as Ycf55. It is found encoded in the chloroplast genomes of algae, it is also found in plants and in the cyanobacteria. The function is unknown, though there are two completely conserved residues (L and D) that may be functionally important. As the family is exclusively found in phototrophic organisms it may play a role in photosynthesis.

Some members of this family are predicted to be response regulators because they contain an N-terminal CheY-like receiver domain.