The introduction to the chapter on protein structure provides an overview of the book's content and structure. It begins with a description of the cover, which features images of protein structures: a Laue x-ray diffraction pattern of the plant enzyme ribulose bisphosphate carboxylase and a spherical virus, the tomato bushy stunt virus. These images highlight the importance of x-ray crystallography in determining protein structures. The chapter then outlines the main topics covered in the book, including the principles of protein structure, the α-domain structures, antiparallel β structures, DNA structures, and various aspects of protein function and engineering. Each section provides an overview of the key concepts, such as the hydrophobic interior of proteins, the formation of domains from structural motifs, and the role of specific motifs in protein function. The content is organized into several chapters, each focusing on different types of protein structures and their functional implications. For example, Chapter 3 discusses α-domain structures, while Chapter 5 covers antiparallel β structures. The book also delves into the structural motifs of eukaryotic transcription factors, the multifunctional nature of DNA polymerase, and the recognition of foreign molecules by the immune system. Overall, the chapter serves as a comprehensive introduction to the diverse and complex world of protein structures, emphasizing their structural diversity and functional significance.The introduction to the chapter on protein structure provides an overview of the book's content and structure. It begins with a description of the cover, which features images of protein structures: a Laue x-ray diffraction pattern of the plant enzyme ribulose bisphosphate carboxylase and a spherical virus, the tomato bushy stunt virus. These images highlight the importance of x-ray crystallography in determining protein structures. The chapter then outlines the main topics covered in the book, including the principles of protein structure, the α-domain structures, antiparallel β structures, DNA structures, and various aspects of protein function and engineering. Each section provides an overview of the key concepts, such as the hydrophobic interior of proteins, the formation of domains from structural motifs, and the role of specific motifs in protein function. The content is organized into several chapters, each focusing on different types of protein structures and their functional implications. For example, Chapter 3 discusses α-domain structures, while Chapter 5 covers antiparallel β structures. The book also delves into the structural motifs of eukaryotic transcription factors, the multifunctional nature of DNA polymerase, and the recognition of foreign molecules by the immune system. Overall, the chapter serves as a comprehensive introduction to the diverse and complex world of protein structures, emphasizing their structural diversity and functional significance.