FIG. 3.

Effect of mutations on the DNase I sensitivity of the amdS promoter. Mycelia were grown for 16 h on 1% glucose plus 10 mM ammonium tartrate. DNA was digested with SacI, and a SacI (−751)/SacII (−227) fragment of the amdS promoter region was used as a probe except as noted otherwise. (A) Strains MH5788 and MH5733 carry a 10-bp oligonucleotide containing a BamHI site inserted into the SmaI (−117) site in the amdS promoter. In strain MH5733 the CCAAT motif is mutated to CAGAT (see Fig. 2). (B) Effect of the hapBCE gene deletions on the DNase I sensitivity of the amdS promoter. In MH9207 hapB is deleted, in MH8194 hapC is deleted, and in MH9206 hapE is deleted. MH3408 is wild type at all hap loci. All strains carry an amdS::lacZ fusion. (C) MH5103 carries a 530-bp BglII (−647)/SmaI (−117) promoter deletion which removes most of the regulatory sites including the CCAAT sequence. In strain MH5095 a 35-bp oligonucleotide carrying the CCAAT motif is inserted into the deletion site (see Fig. 2). DNA was digested with SpeI, and a SpeI (−1008)/XbaI (−650) fragment of the amdS promoter region was used as a probe. The arrowheads indicate internucleosomal cutting of DNase I. (D) In MH8709 the TATA box is mutated as indicated in Fig. 2. Both strains carry an amdS::lacZ fusion gene integrated into the argB locus. DNA was digested with ClaI and a HindIII (+113)/ClaI (+907) fragment of the lacZ coding region was used as a probe. (E) Strain MH6900 carries a 29-bp deletion which removes the two CreA-binding sites.