What is the Origin of Zinc Finger Domain?

The term is descriptive, referencing the finger-like loop structure formed by the amino acid chain folding around the central zinc ion. This motif was first identified in the transcription factor TFIIIA in Xenopus laevis in the 1980s. Its discovery was a breakthrough in understanding how proteins physically interact with the DNA helix to control genetic expression, a process fundamental to the action of steroid and thyroid hormones.

What is the Mechanism of Zinc Finger Domain?

The mechanism centers on the precise, sequence-specific recognition of DNA. The zinc ion stabilizes the domain's three-dimensional structure, allowing the 'finger' to insert into the major groove of the DNA helix. The amino acid residues at the tip of the finger then form sequence-specific hydrogen bonds with the bases of the hormone response element. This highly specific binding allows the nuclear hormone receptor to dimerize, recruit co-activator or co-repressor proteins, and subsequently initiate or repress the transcription of target genes, thereby mediating the hormonal signal.

Zinc Finger Domain ∞ Area

Zinc Finger Domain

Meaning

A zinc finger domain is a small, highly stable protein structural motif characterized by the coordination of one or more zinc ions to stabilize a compact fold, typically involving cysteine and/or histidine residues. This domain functions primarily as a binding interface, allowing proteins to recognize and interact with nucleic acids, such as DNA or RNA, and other proteins. In endocrinology, the zinc finger domain is a crucial structural feature of many nuclear hormone receptors, enabling them to bind to specific hormone response elements (HREs) on the DNA and regulate gene transcription.