The invention features the structural coordinates of a portion of a .alpha.V.beta.3 integrin and the use of the coordinates in methods for identifying molecules which will bind to .alpha.V.beta.3 integrin and, preferably, modulate, e.g., increase or decrease, .alpha.V.beta.3 integrin-mediated adhesion and/or signalling. The identification methods generally involve computer-based structural modelling methods. Such methods can be combined with in vitro or in vivo screening methods to identify candidate therapeutic agent.