Families of Sequence-Specific DNA-Binding Domains in Transcription Factors across the Tree of Life

Control of gene expression by transcription factors (TFs) is essential to determine morphological diversity and complexity in all organisms. Sequence-specific DNA-binding TFs are important for genetic regulation because they directly interpret the genetic code through protein-DNA contacts via DNA-binding domains (DBDs). This chapter demonstrates the current understanding and trends on TF identification and classification in genomes according to DBD families, by summarizing key publications of genome-wide studies of TFs. It surveys TF resources currently available and discusses the criteria and techniques used to attain TF catalogs. The chapter provides an insight into the evolution of TFs in conjunction with the rest of the genes in genomes. It also provides a comprehensive overview of conserved and lineage-specific DBD families. Finally, the chapter reviews interesting domain architectures found in TFs in certain taxonomic groups, using network representation.