HMGB proteins and chromatin structure

HMGBl was first described as a non-histone chromosomal protein [1,80] and has been implicated in the maintenance and establishment of chromatin structure [10] as well as having more recently identified roles. 

The interaction of the abundant HMGB proteins with both nucleosomal particles lacking linker histones and with linker histones themselves in vitro is well documented. A soluble chromatin fraction released from mouse myeloma nuclei contained mononucleosomes associated with almost stoichiometric amounts of HMGB1,2 but lacking histone HI [81]. Nhp6ap binds directly to nucleosomal particles reconstituted with chicken histones (i.e., a single histone octamer 

HMGB proteins including HMGBl ([96,97] A. Simpson and J. O. Thomas, unpublished) and HMG-D [87] can also interact directly in vitro with histone HI. The interaction of HMG-D is independent of the acidic tail (suggesting that, in this case at least, non-specific charge interactions involving the tail can be excluded) but requires aminoacids 75-100, which comprise a short linker and basic region between the HMG box and the tail [87]. 

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