The interaction of nonhistone chromosomal proteins HMG1 and HMG2 with subfractions of H1 histone immobilized on agarose.

Chromatographically isolated subfractions of calf thymus H1 histone have been covalently coupled to agarose beads and tested for their ability to form complexes with the non-histone proteins HMG1 and HMG2 (High Mobility Group proteins, Walker, J.M., Goodwin, G.H. and Johns, E.W. (1976) Eur. J. Biochem. 62, 461-469). When a mixture of HMG1 and HMG2 is passed through a column of H1 histone-agarose, the HMG2 does not bind. HMG1 does bind and can be eluted from the column with NaCl in the range of 0.05 M--0.15 M. The NaCl concentration required to elute HMG1 from each of the three H1 histone subfraction coulmns is different, suggesting that HMG1 has a different binding affinity for the three H1 histone subfractions.