TCDB is operated by the Saier Lab Bioinformatics Group

9.B.394.  The Pentapeptide Repeat-containing Protein (PPRP) Family 

This family includes many proteins which have the PPR in a hydrophilic domain.  Some of them have hydrophobic domains as well, but many do not.  Therefore the PPR domain itself is not involved in transport, but some of these proteins may be. For example, the PPR domain may be present in other proteins in TCDB such as 1.A.1.29.3 and 9.B.65.1.9.