20 Transcriptional Regulation by Homeodomain Proteins: Structural, Functional, and Genetic Aspects

摘要: OVERVIEW The introductory section presents an account of the discovery homeobox and homeodomain, their distribution evolutionary conservation. A description three-dimensional structure homeodomain its binding mode in complexes with DNA then provides basis for a discussion on mechanistic aspects transcriptional regulation by proteins. An appendix gives brief introduction to use nuclear magnetic resonance (NMR) spectroscopy determination proteins protein-DNA at atomic resolution. INTRODUCTION Early History Leading Identification Homeobox In 1934, Thomas H. Morgan proposed theory differential gene activity , which states that each cell multicellular organism only specific set genes, rather than entire genome, is active controls differentiation development (Morgan 1934). On embryological experiments, he suggested initial differences may reside different regions egg cytoplasm they affect genes those nuclei become associated respective cytoplasmic regions. activated would turn cytoplasm, thereby initiating new series reciprocal nucleo-cytoplasm interactions. This has gained strong support during last 60 years forms our thinking about genetic control development. orderly process based coordinated concerted action thousands precise spatial temporal pattern requires regulatory circuits...