Interactions between the subfractons of calf thymus H1 and nonhistone chromosomal proteins HMG1 and HMG2.

The nonhistone chromosomal proteins, HMG1 and HMG2, interact with the various subfractions of calf thymus H1 with a high degree of specificity. Subfractions 1b and 2 interact very strongly with HMG1 to form heterodimers. In contrast, subfractions 3a and 3b interact much more weakly. HMG2 interacts with 3a and 3b but shows no detectable complexing with 1a and 2.