Evidence for the location of high mobility group protein T in the internucleosomal linker regions of trout testis chromatin.

Antibodies against the trout testis non"histone chromosomal protein, high mobility group protein T (HMG-T), have been elicited in goats. The antiserum was shown to be specific for HMG-T and did not cross-react with histone 1 or with the other two trout testis HMG proteins, H6 and ubiquitin. Purified anti-HMG-T IgG was used to determine the location of HMG-T within chromatin subunits separated on sucrose gradients. Binding of fluorescent labeled anti-HMG-T to these subunits clearly supports the notion that this protein is associated not with the nucleosome core but rather with the internucleosomal linker regions, and previously suggested (Levy W., B., Wong, N.C.W., and Dixon, G. H. (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 2810-2814).