Figure 1
From: Water channel pore size determines exclusion properties but not solute selectivity
Structure of the AQP ar/R region. (A) Location of ar/R filter and NPA motifs in AQP structure, exemplified by AQP4 (PDB entry 3GD8). Red spheres indicate oxygen atoms of co-crystallised water molecules. (B) Primary sequence of human AQP4. Residues making up the ar/R selectivity filter are highlighted in red and the conserved NPA motifs in blue. Structures of (C) a GLP and (D) a wAQP are exemplified by AQP3 (shown is a homology model to the GlpF structure; PDB code 1FX8) and AQP4 (PDB code 3GD826). Numbers in brackets refer to the positions defined in the sequence alignment in (E). (E) Sequence alignment of human AQPs and two E. coli AQPs comparing the four regions contributing to the ar/R region. GLPs are highlighted in green. The conserved residues are highlighted in blue; deviations from this are highlighted in red. Panels B-E are reproduced from P. Kitchen PhD thesis35.
