About Karim-Jean Armache's Work
The discovery that eukaryotic DNA is wrapped around the histone octamer and packaged into chromatin transformed our understanding of genome organization and regulation. Yet it also created a conceptual paradox: nucleosomes are the fundamental unit of chromatin and must be sufficiently stable to compact, package, and protect the genome while still allowing enzymes to access DNA. One example of this paradox is transcription, a process essential for all eukaryotic life. All protein-coding genes are transcribed by RNA Polymerase II (Pol II) yet the detailed mechanisms of transcription through chromatin are not understood. We will combine our unique expertise in mechanistic studies of Pol II and nucleosomes and utilize recent technological breakthroughs in structural biology to visualize Pol II transcribing nucleosome bound DNA. Our research will illustrate how transcription functions in the chromatin environment and shed light on how other enzymes access DNA in the context of chromatin.