Structure of H1 and H2 genes

The H1 gene has it own promoter and operator and is physically separated from the hin region The H2 gene is in an operon with the rep gene that encodes a repressor for the H1 gene The promoter for the H2-rep operon lies within the hin region Phase 1: H1 expressed biut H2 worng orientation Phase 2: hin inverts, H2 correct orient., expressed and repressed H1 expression