Low-pass filtered monomer map features of Ca2+/acidic pH (grey) and water structure (green) with differences at lower radius (left). Zoomed inset (right) with maps displayed at a false discovery rate (FDR) threshold of 1% showing significant differences. Detailed map comparison at lower-radius region of Ca2+/acidic pH (grey, left column) with the water condition (green, right column). A total of 3 atomic models (model 1: cyan, model 2: pink, model 3: green) describe the map of TMV in water whereas the Ca2+/acidic pH map could be modelled with a single atomic model (center). Located Ca2+ ion in the Ca2+/acidic pH map with different conformations in the water structure (bottom). 