Histone Cluster 1, H2aa (HIST1H2AA)

The HIST1H2AA gene is the most telomeric H2A gene within the HIST1 cluster. The HIST1 cluster spans over 2 Mb and includes 2 large gaps (over 250 kb each) where there are no histone genes, but many other genes. The organization of histone genes in the mouse Hist1 cluster on chromosome 13A2-A3 is essentially identical to that in human HIST1. The HIST2 cluster on chromosome 1q21 contains 6 histone genes, including 3 H2A genes, and the HIST3 cluster on chromosome 1q42 contains 3 histone genes, including 1 H2A gene (HIST3H2A). Hist2 and Hist3 are located on mouse chromosomes 3F1-F2 and 11B2, respectively. These paired H2A and H2B genes are transcribed from opposite strands, with their 5-prime ends separated by an intergenic region of less than 300 nucleotides.