DSSR-PyMOL cartoon-block schematics: PDB entry 4bhk

PDB-id

4bhk; DSSR-derived features in text and JSON formats

Class

transcription-DNA

Method

X-ray (2.32 Å)

Summary

Crystal structure of moss leafy bound to DNA

Reference

Sayou C, Monniaux M, Nanao MH, Moyroud E, Brockington SF, Thevenon E, Chahtane H, Warthmann N, Melkonian M, Zhang Y, Wong GK, Weigel D, Parcy F, Dumas R (2014): "A Promiscuous Intermediate Underlies the Evolution of Leafy DNA Binding Specificity." Science, 343, 645. doi: 10.1126/SCIENCE.1248229.

Abstract

Transcription factors are key players in evolution. Changes affecting their function can yield novel life forms but also have deleterious effects. Consequently, gene duplication events that release one gene copy from selective pressure are thought to be the common mechanism by which transcription factors acquire new activities. Here we show that LEAFY, a major regulator of flower development and cell division in land plants, underwent changes to its DNA binding specificity, even though plant genomes generally contain a single copy of LEAFY. We examined how these changes occurred at the structural level, and identify an intermediate LEAFY form in hornworts that appears to adopt all different specificities. This promiscuous intermediate could have smoothed the evolutionary transitions thereby allowing LEAFY to evolve new binding specificities while remaining a single copy gene.