To date, at least 14 different helicases have been isolated from single celled organisms, 6 helicases from bacteriophages, 12 from viruses, 15 from yeast, 8 from plants, 11 from calf thymus, and approximately 25 helicases from human cells.
Ata agora foron illadas 14 helicases diferentes de organismos unicelulares, 6 helicases de bacteriófagos, 12 doutros virus, 15 de lévedos, 8 de plantas, 11 do timo de tenreiras, e aproximadamente 25 helicases de células humanas.