Book excerpt: This volume provides a collection of protocols and approaches for the creation of novel ligand binding proteins, compiled and described by many of today's leaders in the field of protein engineering. Chapters focus on modeling protein ligand binding sites, accurate modeling of protein-ligand conformational sampling, scoring of individual docked solutions, structure-based design program such as ROSETTA, protein engineering, and additional methodological approaches. Examples of applications include the design of metal-binding proteins and light-induced ligand binding proteins, the creation of binding proteins that also display catalytic activity, and the binding of larger peptide, protein, DNA and RNA ligands. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls.