Abstract

It has long been assumed that the architectural proteins of chromatin (the histones, for example) are unrelated to their functional proteins (transcription factors, polymerases, etc). New studies(1,2) drastically change this perspective. It appears that a portion of the general transcription initiation complex TFIID is made up of proteins that not only carry marked sequence and structural resemblances to the core histones of the nucleosome, but also form an octameric complex similar to the histone octamer. This can now be seen as part of a general pattern of continuity among structural and functional chromatin proteins.