Different ways to analyze structure may prove insightful in planning ways to experimentally address protein function, e.g mapping conservation onto the protein surface (panel C). It is also possible to use homology modelling to model the effect of site-directed mutagenesis or naturally occurring sequence variants. Changes in surface charge (panels F, G; red = negatively, blue = positively charged) or surface hydrophobicity (panels H, I; green = hydrophobic, blue = hydrophilic)