Two histone fold proteins, CHRAC-14 and CHRAC-16, are developmentally regulated subunits of chromatin accessibility complex (CHRAC)

The ISWI ATPase of Drosophila is a molecular engine that can drive a range of nucleosome remodelling reactions ire vitro. ISWI is important for cell v iability, developmental gene expression and chromosome structure. It intera cts with other proteins to form several distinct nucleosome remodelling mac hines. The chromatin accessibility complex (CHRAC) is a biochemical entity containing ISWI in association with several other proteins. Here we report on the identification of the two smallest CHRAC subunits, CHRAC-14 and CHRA C-16. They contain histone fold domains most closely related to those found in sequence-specific transcription factors NF-YB and NF-YC, respectively, CHRAC-14 and CHRAC-16 interact directly with each other as well as with ISW I, and are associated with functionally active CHRAC. The developmental exp ression profiles of both subunits suggest specialized roles in chromatin re modelling reactions in the early embryo for both histone fold subunits.