Coiled Coil Domain Containing Protein 93 (CCDC93)

Coiled-coil domain-containing protein 93 is a protein encoded by the CCDC93 gene. The coiled coil is a common structural motif, formed by approximately 3 ± 5% of all amino acids in proteins. Typically, it consists of two to five -helices wrapped around each other into a left-handed helix to form a supercoil. Whereas regular -helices go through 3.6 residues for each complete turn of the helix, the distortion imposed upon each helix within a left-handed coiled coil lowers this value to around 3.5. Thus a heptad repeat occurs every two turns of the helix. The coiled coil was firstdescri bed by Crick in 1953. Coiled coils usually contain a repeated pattern, hxxhcxc, of hydrophobic (h) and charged (c) amino-acid residues, referred to as a heptad repeat.