Living organisms carefully control the activity of their genes. This control is exercised by special proteins, called transcription factors, which bind to specific regions of DNA near the genes they regulate. A few years ago, ALOG proteins were discovered exclusively in plants: they play important roles (in moss, pea, rice or tomato) and are thought to correspond to new transcription factors. It was therefore necessary to conduct research to understand how they work.
Researchers at IRIG have studied the ALOGs of the plant model
Arabidopsis Thaliana. They were able to identify the DNA motif they recognize and show that it is the same in all land plants. Resolution of the crystallographic structure of the ALOG/DNA complex revealed a new mode of DNA binding (ESRF Grenoble collaboration). In partnership with the University of Milan, scientists have shown that, in Arabidopsis, ALOGs prevent a bract from growing beneath the flowers (a small leaf present in many species).
Figure: DNA-binding domain (orange) of the ALOG protein (green). A Zn atom is present (in red). Credit CEA
The collection of plant transcription factors has been enriched by a new family: the ALOG family [1,2]. This biochemical and structural work will serve as the basis for numerous functional studies in rice ears, tomato bunches or air nitrogen fixation in legumes.
These works are supported by Ubiflor ANR project