This is family contains the KID repeat as found in Borrelia spirochete RepA / Rep+ proteins. The function of these proteins is unknown. RepA and related Borrelia proteins have been suggested to play an important genus-wide role in the biology of the Borrelia [1].

1: Cloning and molecular characterization of a multicopy, linear plasmid-carried, repeat motif-containing gene from Borrelia turicatae, a causative agent of relapsing fever. Carlyon JA, Marconi RT; J Bacteriol 1998;180:4974-4981. PMID:9733706