Fig. 2.

TATA box and activator motif mutations decrease ε-globin transcription and promoter accessibility. The promoter transcription activator motifs indicated in Fig. 1 A were destroyed by clustered point mutations (38). (A) Representative RNase protection analysis of RNA from K562 clones carrying HS2ε-globin genes with mutations in promoter GATA, CACC, or TATA motifs. Controls include wild-type HS2ε, an enhancerless ε-globin gene (ε), and one linked to MARE mutant HS2 (ΔNF-E2). The endogenous and minichromosomal ε-globin signals are indicated. M, markers between 75 and 298 bp. (B) Representative analysis of AvaII accessibility within N1– (see Fig. 1A) for the mutant clones. M, markers between 1.6 and 3 kb. (C) The RNase protection results illustrated in A are depicted graphically on the left (averages of two or three determinations for each clone ± SEM). Quantitation of the AvaII cutting [cut/(uncut + cut)] illustrated in B is depicted graphically at the right (two or three determinations for each clone ± SEM).