Am. Duchene et al., TRANSCRIPTIONAL ANALYSIS OF GROEL GENES IN STREPTOMYCES-COELICOLOR A3(2), MGG. Molecular & general genetics, 245(1), 1994, pp. 61-68
In Streptomyces coelicolor A3(2), synthesis of the groES, groES-groEL1
and groEL2 transcripts is induced either by heat shock or by undefine
d physiological stress signals present at a certain stage of growth. U
nder all conditions tested, transcription of groES and gsoES-groEL1 or
iginated from a unique start site upstream of groES, whereas transcrip
tion of groEL2 originated from a unique site upstream of groEL2. RNA p
olymerase isolated either from heat-shocked or control mycelia allowed
in vitro transcription from the P1 promoter of groES/EL1 and the P2 p
romoter of groEL2. The fact that these two RNA polymerase preparations
both initiated transcription with equal efficiency from the same site
s suggested that a heat shock-specific sigma factor is not responsible
for the temperature-induced transcription of groE genes. Instead, reg
ulation of these genes from vegetative-type promoters may be effected
by a DNA-binding protein observed in gel retardation assays, which rec
ognizes a motif found in the groE and dnaK promoter regions of many pr
okaryotic genes.