Fig. 1
From: Impaired phosphate transport in SLC34A2 variants in patients with pulmonary alveolar microlithiasis
Predicted model of the secondary topology of the human NaPi-IIb protein; the locations of the four investigated variants are indicated. The current model of SLC34 transporters based on homology modeling with the bacterial dicarboxylate cotransporter VcINDY as a template, was adapted from the model of the predicted structure of human NaPi-IIa by Fenollar-Ferrer et al. [12]. The Na1-binding site is presumed to be formed by the amino acids T197 (Thr), Q203 (Gln), D206 (Asp), N224 (Asn), and S461 (Ser), the Na2-binding site by S161 (Ser), T192 (Thr), S193 (Ser), and N196 (Asn), the Pi-binding site by S161 (Ser) and S433 (Ser), and the Na3-binding site by Q431 (Gln), S432 (Ser), S433 (Ser), T465 (Thr), and T468 (Thr) [13]. The protein sequences used for alignment in Clustal Omega version 1.2.4 [14]: Ensembl Transcript ID ENST00000382051.7 and Transcript ID ENST00000324417.5 release 92 (Human (GRCh38.p12) assembly), and Ensembl Transcript ID ENSRNOT00000033749.5 (Rat (Rnor_6.0) assembly). A (Ala), R (Arg), N (Asn), D (Asp), E (Glu), G (Gly), I (Ile), L (Leu), P (Pro), F (Phe), S (Ser), T (Thr), Y (Tyr)