The results indicated that these two sigma
factors regulated expression of acry1Aa9-9lacZtranscriptional
fusion in vivo. The s
K
mutant produced about 50% lessb-galactosidase than the wild-type strain whereas nob-galac-tosidase synthesis was obtained in thes
E
mutant. The latter
result was anticipated ass
E
controlss
K
synthesis. Consensus
sequences of promoters recognized byB. thuringiensisRNA
polymerase containings
E
ors
K
have been deduced from the
alignment of the promoter regions of these genes.
47
The re-sults indicate that the transcription ofcry1Bais likely to bes
E
ors
K
dependent. The mRNAs encoding the crystal proteins
have average half-lives of 10 min. These are among relatively
long-lived mRNAs present in B. thuringiensisduring its sta-tionary phase.
48
The putative transcriptional terminator of
cry1Aagene (a stem-loop structure) acts as a positive retro-
isolated. In vitro transcription experiments have also indi-cated that othercrygenes (e.g.cry1Ba) contain either BtI alone
or BtI with BtII