There is an urgent need to augment the widely-used and well-tolerated but drug resistance susceptible triazole antifungals with broad-spectrum drugs that target fungal lanosterol 14α-demethylase (CYP51) and not its human homologue or other cytochrome 450 enzymes. We have obtained high-resolution X-ray crystal structures of wild type and triazole resistant CYP51s with substrates and triazole inhibitors. We will apply this unique knowledge to improve drug specificity by modifying several features of existing antifungals. The electron transfer pathway to the active site and a product egress pathway will also be explored to identify antifungals that separately target human and plant fungal pathogens. Our structural biology expertise, combinatorial chemistry capacity, yeast-based screens and relevant murine infection models will be used to identify optimal hits as fungal CYP51-specific drug candidates. The identification of new antifungals will provide a model for drug discovery and development that circumvents the ubiquitous activities of cytochrome P450 enzymes.