The alteration of chromatin structure plays an integral role in gene regulation. One means by which eukaryotes manipulate chromatin structure involves the use of ATP-dependent chromatin-remodelling enzymes. It appears likely that these enzymes play a widespread role in the regulation of many nuclear processes. Recently, significant progress has been made in defining the alterations to chromatin structure that these enzymes generate. The ability to alter nucleosome positioning may be a common feature of all ATP-dependent remodelling enzymes, but the spectrum of positions to which nucleosomes are relocated varies. Mounting evidence supports the ability of remodelling enzymes to translocate along DNA. This provides a means by which they could alter both the twist and writhe of DNA on the surface of nucleosomes, and so accelerate nucleosome repositioning.
Abbreviations used: CSF-1, colony-stimulating factor-1; ISWI, imitation switch; SNF, sucrose non-fermenting; SWI, switching (of yeast mating-type).