Figure 1.

Structure of OsNramp5 and putative amino acids of the metal-binding site involving metal uptake efficiency and selectivity. (A) Topological diagram of OsNramp5 structure. The diagram was depicted based on the domain architecture of UniProt Q8H4H5, with modifications of Figure 3A in Bozzi and Gaudet, 2021. The OsNramp5 consists of 12 transmembrane regions. The asterisk denotes the location of the metal-binding site composed of TM1 and TM6. The putative key amino acid residues for the metal binding are designated as #2, #5, #8, and #11. (B) Phylogenetic tree and amino acid composition of metal-binding sites of 21 Nramps in various organisms (Os, Oryza sativa; Zm, Zea mays; At, Arabidopsis thaliana; Sca, Staphylococcus capitis; Dra, Deinococcus radiodurans). The amino acid species of #1 to #12 are shown in capital single letter, with the metal uptake characteristics: +, transport; -, no transport;?, promiscuous;/, not confirmed (a: Curie et al., 2000, b: Takahashi et al., 2011, c: Tiwari et al., 2014, d: Chang et al., 2020, e: Ishimaru et al., 2012, f: Ishikawa et al., 2012, g: Sasaki et al., 2012, h: Sui et al., 2018, i: Peris-Peris et al., 2017, j: Xia et al., 2010, k: Li et al., 2022, l: Yamaji et al., 2013, m: Yang et al., 2013, n: Thomine et al., 2000, o: Cailliatte et al., 2009, p: Li et al., 2019, q: Pottier et al., 2015, r: Alejandro et al., 2017, s: Gao et al., 2018, t: Zhao et al., 2018, u: Guo et al., 2022, v: Li et al., 2023, w: Ehrnstorfer et al., 2014, x: Bozzi et al., 2016a, y: Bozzi et al., 2016b).