RIBOSOMAL-RNA SYNTHESIS IN STREPTOMYCES-LIVIDANS UNDER HEAT-SHOCK CONDITIONS

Clones containing rRNA genes were isolated from a gene library of Stre ptomyces lividans when RNA produced under heat shock conditions was us ed as a probe. Two of the clones carried entire rRNA operons rrnA and rrnF respectively, the expression of both operons being under the cont rol of four different promoters. At least two of the promoters were fu lly functional when the temperature increased from 30 to 45 degrees C, ensuring transcription of the rRNA genes under the heat shock. A thir d clone carried a partial rRNA operon in which expression was controll ed by a main promoter that was functional at both 30 and 45 degrees C. (C) 1997 Elsevier Science B.V.