Figure 1.

Rat ɛ subunit promoter expression constructs. Schematic representation of expression constructs harboring the luciferase (Luc) structural gene driven either by a wild-type ɛ subunit promoter (ɛ-5000) or its various 5′ (ɛ-108 and ɛ-69) or 3′ (ɛ3′Δ54 and ɛ3′Δ65) deletion mutants. Dotted lines indicate the portion of DNA deleted to generate deletions. Mutations 1 and 2, respectively, represent the site-directed mutagenesis (shown in boldface type) of nucleotides CCGG (positions −59 and −56) to TTTA (ɛMUT1) and nucleotides TAGT (positions −63 and −60) to CGAC (ɛMUT2). The position of the transcriptional start site is indicated by an arrow.