7NL4

OsNIP2;1 silicon transporter from rice

Summary for 7NL4

• Entry DOI: 10.2210/pdb7nl4/pdb
• Descriptor: Aquaporin NIP2-1, CADMIUM ION (2 entities in total)
• Functional Keywords: aquaporin membrane transporter metalloids osnip2;1, membrane protein
• Biological source: Oryza sativa subsp. japonica (Rice)
• Total number of polymer chains: 8
• Total formula weight: 192859.70

Authors

van den Berg, B. (deposition date: 2021-02-22, release date: 2021-11-03, Last modification date: 2024-01-31)

Primary citation

van den Berg, B.,Pedebos, C.,Bolla, J.R.,Robinson, C.V.,Basle, A.,Khalid, S.
Structural Basis for Silicic Acid Uptake by Higher Plants.
J.Mol.Biol., 433:167226-167226, 2021

PubMed 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.

PubMed: 34487790
DOI: 10.1016/j.jmb.2021.167226

Experimental method

X-RAY DIFFRACTION (3 Å)