5L25

Crystal Structure of Arabidopsis thaliana Bor1

Summary for 5L25

• Entry DOI: 10.2210/pdb5l25/pdb
• Descriptor: Boron transporter 1 (1 entity in total)
• Functional Keywords: membrane protein, slc4, anion exchanger, transport protein
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 1
• Total formula weight: 73265.52

Authors

Thurtle-Schmidt, B.H.,Stroud, R.M. (deposition date: 2016-07-31, release date: 2016-09-14, Last modification date: 2023-10-04)

Primary citation

Thurtle-Schmidt, B.H.,Stroud, R.M.
Structure of Bor1 supports an elevator transport mechanism for SLC4 anion exchangers.
Proc.Natl.Acad.Sci.USA, 113:10542-10546, 2016

PubMed Abstract: Boron is essential for plant growth because of its incorporation into plant cell walls; however, in excess it is toxic to plants. Boron transport and homeostasis in plants is regulated in part by the borate efflux transporter Bor1, a member of the solute carrier (SLC) 4 transporter family with homology to the human bicarbonate transporter Band 3. Here, we present the 4.1-Å resolution crystal structure of Arabidopsis thaliana Bor1. The structure displays a dimeric architecture in which dimerization is mediated by centralized Gate domains. Comparisons with a structure of Band 3 in an outward-open state reveal that the Core domains of Bor1 have rotated inwards to achieve an occluded state. Further structural comparisons with UapA, a xanthine transporter from the nucleobase-ascorbate transporter family, show that the downward pivoting of the Core domains relative to the Gate domains may access an inward-open state. These results suggest that the SLC4, SLC26, and nucleobase-ascorbate transporter families all share an elevator transport mechanism in which alternating access is provided by Core domains that carry substrates across a membrane.

PubMed: 27601653
DOI: 10.1073/pnas.1612603113

Experimental method

X-RAY DIFFRACTION (4.11 Å)