Zinc Fingers

Jack of All Trades

Zinc fingers come in many shapes and sizes, but they all have one or more zinc atoms (shown here in green) gripped by a combination of four amino acids, either cysteine or histidine (shown on the next page). Zinc fingers perform many different jobs, as shown in these three sample structures. The complex at upper left (PDB entry 1y0j) shows zinc fingers from two longer proteins, GATA-1 (which contains two zinc fingers) and FOG-1 (which contains 9 zinc fingers). The specific interaction between these two zinc fingers plays an essential role in the development of blood cells. The HIV-1 nucleocapsid protein shown at lower left (PDB entry 1a1t) contains two zinc fingers that grip the viral RNA during budding of the virus. The protein EEA1, shown at the right from PDB entry 1joc, contains two zinc fingers in each chain. It binds to a special lipid found in endosomes, and plays an essential role in transporting molecules to that cellular compartment.