Protein Motifs: Zinc Fingers

Abstract

Zinc is a catalytic, structural and regulatory ion involved in a wide variety of biological processes. It is essential for stabilising the fold of biomolecules called ‘zinc finger’, a term that originates from the finding of the particular organisation of zinc coordinating amino-acids in the primary sequence of the TFIIIA transcription factor. Zinc fingers currently designate a vast family of protein domains and folds found in proteins involved in both protein–nucleic acids and protein–protein interactions. The variety of folds stabilised by zinc as well as genome sequence analysis suggests that zinc has played an important role in the evolution of the proteome. The modular structure of zinc fingers allowed the design of very specific DNA- and RNA-binding proteins opening a wide range of applications such as artificial nucleases or transcription factors.

Key Concepts

• Zinc fingers are small folded protein domains, involved in numerous biological processes.
• Zinc coordination by proteins allowed the evolution of a wide variety of folds.
• Zinc ions have a wide range of affinities for proteins zinc-binding sites, allowing metal exchange.
• Zinc fingers are involved in protein–protein and protein–DNA interactions.
• The rules underlying the specific recognition of DNA sequences by C2H2 zinc fingers are known, enabling the design of artificial DNA enzymes.