Unlocked enzyme structure shows how strigolactone hormone controls plant growth

Plants have to continually adapt to the changing environment. Plants have evolved mechanisms to sense and respond to the environment and integrate signals from outside with their own programs.

A new research from the UC Davis College of Biological Sciences has shown how the underlying mechanism of the plant hormone signaling pathway can be untangled.

Shabek is the assistant professor of biochemistry and structural biology in the Department of Plant Biology.

Shabek's work stems from a study published in Nature in 2018, unraveling the changes in MAX2 and D3 ubiquitin ligase. MAX2 can recruit a strigolactone sensor, D14, and target for destruction a DNA transcriptional repressor complex, D53, in locked or unlocked forms. Ubiquitins are small proteins found in all eukaryotes and are used to destroy a cell.

The approach used to find the key to MAX2 was integrated with advanced structural biology, biochemistry, and plant genetics.

Shabek said that they created a MAX2 stuck in an unlocked form by using structure-guided approaches.

A massive network of genes.

MAX2 can target the repressor proteins and decorate them with small ubiquitin proteins, which can be used to destroy them. Shabek said that removing the repressors allows other genes to be expressed.

Sending the repressors to the disposal complexes requires theidase to relock. The strigolactone sensor is destroyed when MAX2 is locked, returning the system to its original state.

The key to the lock can be directly triggered by an organic acid metabolite.

This is the first work that placed a primary metabolite as a direct new regulator of this type of ubiquitin ligase enzymes and will open new avenues of study in this direction.

The Department of Plant Biology has two additional coauthors on the paper. The Advanced Light Source is a U.S. Department of Energy user facility.

More information: Lior Tal et al, A conformational switch in the SCF-D3/MAX2 ubiquitin ligase facilitates strigolactone signalling, Nature Plants (2022). DOI: 10.1038/s41477-022-01145-7 Journal information: Nature Plants , Nature Citation: Unlocked enzyme structure shows how strigolactone hormone controls plant growth (2022, April 28) retrieved 29 April 2022 from https://phys.org/news/2022-04-enzyme-strigolactone-hormone-growth.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.