Abstract
Some of the key processes in living organisms remain essentially unchanged even in evolutionarily very distant species. Transcriptional regulation is one such fundamental process that is essential for cell survival. Transcriptional control exerts great part of its effects at the level of transcription initiation mediated through protein-DNA interactions mainly at promoters but also at other control regions. In this chapter, the authors identify conserved families of motifs of promoter regulatory structures between Homo sapiens, Mus musculus and Drosophila melanogaster. By a promoter regulatory structure they consider here a combination of motifs from identified motif families. Conservation of promoter structure across these vertebrate and invertebrate genomes suggests the presence of a fundamental promoter architecture and provides the basis for deeper understanding of the necessary components of the transcription regulation machinery. The authors reveal the existence of families of DNA sequence motifs that are shared across all three species in upstream promoter regions. They further analyze the relevance of our findings for better understanding of preserved regulatory mechanisms and associated biology insights.