The reversible ubiquitylation of histone H2B has long been known to regulate gene transcription, and is now understood to modulate DNA replication as well. In this review, we describe how recent, genome-wide analyses have demonstrated that this histone mark has further reaching effects on transcription and replication than once thought. We also consider the ongoing efforts to elucidate the molecular mechanisms by which H2B ubiquitylation affects processes on the DNA template, and outline the various hypothetical scenarios.
Keywords: ARS, autonomous replication site; DNA replication; H2B ubiquitylation; H2Bub, monoubiquitylated H2B; HU, hydroxyurea; RNAP II, RNA Polymerase II; SAGA, Spt-Ada-Gcn5 acetyltransferase; chromatin; histone modification, transcription; ssDNA, single-stranded DNA.