Cloning of the cDNA encoding a novel subtype of histone H1

The H1 class of histones is implicated in organizing a higher order of chromatin structure and in involvement with transcriptional repression. They compromise multiple subtypes that presumably have a specific function. We report here the isolation and characterization of a human cDNA encoding a novel subtype of histone H1. It is the most distantly related subtype of mammalian H1 reported to date. However, it still shares the characteristic features of H1: the tripartite structure, conservation in the globular domain, the profile of hydropathy and the basic isoelectric point. The expression of this H1 subtype was ubiquitously observed in all tissues examined. Our findings suggest that novel subtypes of H1 may remain unidentified in mammals.