8IRM

Endogenous substrate adenine bound state of Arabidopsis AZG1 at pH 5.5

Summary for 8IRM

• Entry DOI: 10.2210/pdb8irm/pdb
• EMDB information: 35679
• Descriptor: Adenine/guanine permease AZG1, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ADENINE, ... (4 entities in total)
• Functional Keywords: cytokinin, transporter, transport protein
• Biological source: Arabidopsis thaliana (thale cress)
• Total number of polymer chains: 2
• Total formula weight: 132492.46

Authors

Xu, L.,Guo, J. (deposition date: 2023-03-19, release date: 2024-01-17, Last modification date: 2024-11-20)

Primary citation

Xu, L.,Jia, W.,Tao, X.,Ye, F.,Zhang, Y.,Ding, Z.J.,Zheng, S.J.,Qiao, S.,Su, N.,Zhang, Y.,Wu, S.,Guo, J.
Structures and mechanisms of the Arabidopsis cytokinin transporter AZG1.
Nat.Plants, 10:180-191, 2024

PubMed Abstract: Cytokinins are essential for plant growth and development, and their tissue distributions are regulated by transmembrane transport. Recent studies have revealed that members of the 'Aza-Guanine Resistant' (AZG) protein family from Arabidopsis thaliana can mediate cytokinin uptake in roots. Here we present 2.7 to 3.3 Å cryo-electron microscopy structures of Arabidopsis AZG1 in the apo state and in complex with its substrates trans-zeatin (tZ), 6-benzyleaminopurine (6-BAP) or kinetin. AZG1 forms a homodimer and each subunit shares a similar topology and domain arrangement with the proteins of the nucleobase/ascorbate transporter (NAT) family. These structures, along with functional analyses, reveal the molecular basis for cytokinin recognition. Comparison of the AZG1 structures determined in inward-facing conformations and predicted by AlphaFold2 in the occluded conformation allowed us to propose that AZG1 may carry cytokinins across the membrane through an elevator mechanism.

PubMed: 38172575
DOI: 10.1038/s41477-023-01590-y

Experimental method

ELECTRON MICROSCOPY (2.6 Å)