ABSTRACT
The discovery and subsequent initial characterization of the group of chromosomal proteins called the High Mobility Group (HMG) proteins has created considerable interest because of the suggestion that they may be associated with active genes. The HMG proteins prepared by extraction methods are recovered in a denatured state due to the exposure to acids. The possible association of HMG proteins with single-stranded deoxyribonucleic acid (DNA) might suggest that HMG 1 and 2 are acting as DNA helix-unwinding proteins during DNA replication. Chemical cross-linking studies on chromatin have shown that HMG 1 may be associated as oligomers or at least sequestered in specific regions of the genome. HMG14 and HMG17 bind to DNA by ionic interactions between basic amino acids and the DNA phosphate groups. The possibility that postsynthetic modifications of the HMG14 and 17 proteins play a role in modulating gene transcription will also be an important line of investigation in future studies.
