The cyanobacterial clock proteins KaiA and KaiB are proposed as regulators of the circadian rhythm in cyanobacteria. Mutations in both proteins have been reported to alter or abolish circadian rhythmicity. KaiB adopts an alpha-beta meander motif and is found to be a dimer [1].

1: Anabaena circadian clock proteins KaiA and KaiB reveal a potential common binding site to their partner KaiC. Garces RG, Wu N, Gillon W, Pai EF; EMBO J 2004;23:1688-1698. PMID:15071498