Structure, function, and protein taxonomy

This paper considers two recent arguments that structure should not be regarded as the fundamental individuating property of proteins. By clarifying both what it might mean for certain properties to play a fundamental role in a classification scheme and the extent to which structure plays such a role in protein classification, I argue that both arguments are unsound. Because of its robustness, its importance in laboratory practice, and its explanatory centrality, primary structure should be regarded as the fundamental distinguishing characteristic of protein taxonomy.