The enormously diverse complexity seen amongst individual
species within the animal kingdom evolved from a surprisingly
small gene pool. For example, mice effectively serve as medical
research models because humans and mice share 80-percent of the
same protein-coding genes. The key to morphological and
behavioral complexity, a growing body of scientific evidence
suggests, is the regulation of gene expression by a family of
DNA-binding proteins called “transcription factors.” Now, a team
of researchers with the U.S. Department of Energy’s Lawrence
Berkeley National Laboratory (Berkeley Lab) and the University
of California (UC) Berkeley has discovered the secret behind how
one these critical transcription factors is able to perform – a
split personality. Using a technique called single-particle
cryo-electron microscopy, the team, which was led by
biophysicist Eva Nogales, showed that the transcription factor
known as “TFIID” can co-exist in two distinct structural states.
These two states – the canonical and t