The frequency clock protein, is the central component of the frq-based circadian negative feedback loop, regulates various aspects of the circadian clock in Neurospora crassa [2]. This protein has been shown to interact with itself via a coiled-coil [2].

1: The frq locus in Neurospora crassa: a key element in circadian clock organization. Gardner GF, Feldman JF; Genetics. 1980;96:877-886. PMID:6455327

2: Coiled-coil domain-mediated FRQ-FRQ interaction is essential for its circadian clock function in Neurospora. Cheng P, Yang Y, Heintzen C, Liu Y; EMBO J. 2001;20:101-108. PMID:11226160