HMGN stands for High Mobility Group Nucleosome-binding. HMGN proteins are members of the broader class of High mobility group (HMG) chromosomal proteins that help in transcription, replication, recombination, and DNA repair.
Though identified more than 30 years back, little is known about the actual role of these basic proteins. There are several types of HMGN proteins; N1, N2, N3, N4 & N5. Many of these are conserved among the higher eukaryotes.
HMGNs are non-histone proteins, which associate with nucleosomes to control transcription of genes. HMGNs control transcription by altering the interaction of histone H1 with nucleosomes to maintain a decondensed chromatin structure.