2.A.49.3.1
NO₃^-:H⁺ (or less efficiently, Cl^-:H⁺) antiporter, ClC-A or CLCa (De Angeli et al., 2006; Bergsdorf et al., 2009). Responsible for nitrate uptake into vacuoles (Zifarelli and Pusch, 2009b).  It is up-regulated under salt stress conditions (Yang et al. 2018) and may play a role in nitrate and Cd²⁺ resistance (Liao et al. 2019). The cryoEM structure has been solved at 2.8 Å resolution. An almost identical sequence has Uniprot acc # P92941 and differs from the one included in TCDB between residues 380 and 430, possibly due to sequencing errors. The central nitrate is shifted by approximately 1.4 Å from chloride, which is likely caused by a weaker interaction between the anion and Pro160; the side chains of aromatic residues around the central binding site are rearranged to accommodate the larger nitrate (He et al. 2022). The regulatory mechanisms of AtCLCa by nucleotides and phospholipids have been proposed (Yang et al. 2018) and may play a role in nitrate and Cd²⁺ resistance (Liao et al. 2019). The cryoEM structure has been solved at 2.8 Å resolution. An almost identical sequence has Uniprot acc # P92941 and differs from the one included in TCDB between residues 380 and 430, possibly due to sequencing errors. The central nitrate is shifted by approximately 1.4 Å from chloride, which is likely caused by a weaker interaction between the anion and Pro160; the side chains of aromatic residues around the central binding site are rearranged to accommodate the larger nitrate (He et al. 2022). The regulatory mechanisms of AtCLCa by nucleotides and phospholipids have been proposed (Yang et al. 2023).