Differences between some properties of acetylated and nonacetylated forms of HMG1 protein

There are data suggesting that HMG1 protein may be involved in DNA replication. Recently we have found that only the acetylated form of the protein generates tetramers, stimulates the activity of DNA polymerase alpha (EC 2.7.7.7) (with activated DNA as a template) and forms a specific complex with it. This paper compares some properties of the acetylated and nonacetylated forms of HMG1 protein and shows that it is only the acetylated form which serves as a histone assembly factor, increases the melting temperature of poly d(A-T)] and stimulates the activity of DNA polymerase alpha when histone H1-depleted chromatin is used as a template.