Hmo1: A versatile member of the high mobility group box family of chromosomal architecture proteins

Figure 3 Model for the gene boundary function of Hmo1. A: Hmo1 binds cruciform structure that may form in negatively supercoiled gene boundaries; B: Diagram of a gene loop structure. The transcriptional start site, transcriptional termination site and gene boundaries are indicated. An RNA polymerase II (RNAPII) transcribing the gene is shown. Note, more than one RNAPII may transcribe the gene at the same time. Hmo1 binds gene boundaries and help maintain the negative supercoiling of DNA in them. Dimerization/oligomerization of Hmo1 promotes the formation and maintenance of gene loop. RNAPII: RNA polymerase II; TSS: Transcriptional start site; TTS: Transcriptional termination site.