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Structural basis for silicic acid uptake by higher plants

DOI: 10.1016/j.jmb.2021.167226 DOI Help

Authors: Bert Van Den Berg (Newcastle University) , Conrado Pedebos (University of Southampton; University of Oxford) , Jani R. Bolla (University of Oxford; The Kavli Institute for Nanoscience Discovery) , Carol V. Robinson (University of Oxford; The Kavli Institute for Nanoscience Discovery) , Arnaud Basle (Newcastle University) , Syma Khalid (University of Southampton; University of Oxford)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Molecular Biology , VOL 433

State: Published (Approved)
Published: October 2021

Open Access Open Access

Abstract: Many of the world's most important food crops such as rice, barley and maize accumulate silicon (Si) to high levels, resulting in better plant growth and crop yields. The first step in Si accumulation is the uptake of silicic acid by the roots, a process mediated by the structurally uncharacterised NIP subfamily of aquaporins, also named metalloid porins. Here, we present the X-ray crystal structure of the archetypal NIP family member from Oryza sativa (OsNIP2;1). The OsNIP2;1 channel is closed in the crystal structure by the cytoplasmic loop D, which is known to regulate channel opening in classical plant aquaporins. The structure further reveals a novel, five-residue extracellular selectivity filter with a large diameter. Unbiased molecular dynamics simulations show a rapid opening of the channel and visualise how silicic acid interacts with the selectivity filter prior to transmembrane diffusion. Our results will enable detailed structure–function studies of metalloid porins, including the basis of their substrate selectivity.

Journal Keywords: silicic acid transport; NIP channel; aquaporin; X-ray crystal structure; molecular dynamics

Diamond Keywords: Biofortification

Subject Areas: Biology and Bio-materials

Instruments: I24-Microfocus Macromolecular Crystallography

Added On: 13/10/2021 11:25


Discipline Tags:

Plant science Life Sciences & Biotech Agriculture & Fisheries Structural biology

Technical Tags:

Diffraction Macromolecular Crystallography (MX)