Evolution of Zinc Finger Protein Diversity

A large number of transcription factors in humans belong to a superfamily that shares a similar motif known as the zinc finger. Among these, a large proportion have multiple tandem repeats, and are known as poly zinc finger (polyZF) proteins. These proteins can have anywhere from 4 to 30 repeating units, existing mainly in tandem and highly homologous in terms of spacing and size. The human genome encodes nearly 700 of these type of transcriptional repressors, but their main functions are largely undeciphered. What's more, evolutionary analysis has revealed that these hundreds of similarly structured proteins evolved from a very small pool of ancestors. Over the years, repeated duplications of the zinc finger region have lead to gene diversity, and differences in protein structure suggest a multitude of diverging roles in several lineages of different species, including fish, humans and other primates, and mice.

_Source:

Emerson, R. and Thomas, J. 2009. Adaptive evolution in zinc finger transcription factors. PLOS Genetics 5(1) e1000325, doi:10.1371/journal.pgen.1000325.