PDBsum entry 5a2o

Transport protein

PDB id: 5a2o

Contents

Protein chains

470 a.a.

Ligands

NO3 ×2

PDB id:

5a2o

Name:

Transport protein

Title:

Crystal structure of the nitrate transporter nrt1.1 from arabidopsis thaliana in complex with nitrate.

Structure:

Nitrate transporter 1.1. Chain: a, b. Engineered: yes

Source:

Arabidopsis thaliana. Thale cress. Organism_taxid: 3702. Expressed in: saccharomyces cerevisiae. Expression_system_taxid: 4932. Other_details: cloned from tair abrc stock clone u15475

Resolution:

3.71Å R-factor: 0.289 R-free: 0.328

Authors:

J.L.Parker,S.Newstead

Key ref:

J.L.Parker and S.Newstead (2014). Molecular basis of nitrate uptake by the plant nitrate transporter NRT1.1. Nature, 507, 68-72. PubMed id: 24572366 DOI: 10.1038/nature13116

Date:

20-May-15 Release date: 17-Jun-15

Supersedes:

4cl5

Protein chains

Q05085  (PTR7_ARATH) -  Protein NRT1/ PTR FAMILY 6.3 from Arabidopsis thaliana

Seq: 590 a.a.

Struc: 470 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1038/nature13116

Nature 507:68-72 (2014)

PubMed id: 24572366

Molecular basis of nitrate uptake by the plant nitrate transporter NRT1.1.

J.L.Parker, S.Newstead.

ABSTRACT

The NRT1/PTR family of proton-coupled transporters are responsible for nitrogen assimilation in eukaryotes and bacteria through the uptake of peptides. However, in most plant species members of this family have evolved to transport nitrate as well as additional secondary metabolites and hormones. In response to falling nitrate levels, NRT1.1 is phosphorylated on an intracellular threonine that switches the transporter from a low-affinity to high-affinity state. Here we present both the apo and nitrate-bound crystal structures of Arabidopsis thaliana NRT1.1, which together with in vitro binding and transport data identify a key role for His 356 in nitrate binding. Our data support a model whereby phosphorylation increases structural flexibility and in turn the rate of transport. Comparison with peptide transporters further reveals how the NRT1/PTR family has evolved to recognize diverse nitrogenous ligands, while maintaining elements of a conserved coupling mechanism within this superfamily of nutrient transporters.