Mongkolsuk S, Lovett P S
Proc Natl Acad Sci U S A. 1984 Jun;81(11):3457-60. doi: 10.1073/pnas.81.11.3457.
The cat-86 gene in plasmid pPL603 specifies chloramphenicol acetyltransferase (CAT) and is selectively expressed in Bacillus subtilis at a stage in sporulation in which internal spores are first observed (approximately T8). The gene is unexpressed in vegetatively growing cells. cat-86 expression and spore formation are both blocked when cells are grown in excess glucose. cat-86 expression at T8 is due to selective transcription of the gene, since cat-86 mRNA is undetectable in vegetatively growing cells but is readily demonstrated in sporulating cells. The transcription start site for cat-86 mRNA from sporulating cells is within a 203-base-pair restriction fragment designated P1, which is located upstream from the cat coding region on pPL603 . Deletion of P1 from pPL603 eliminates the sporulation -associated expression of cat-86. Host sporulation genes, whose function is absolutely required for cat-86 expression at T8, include six early sporulation, spo0 , genes and spoIIE . Therefore, pPL603 provides a novel system in which the in vivo expression of a known, plasmid-linked gene is dependent on sporulation-specific changes in B. subtilis.
质粒pPL603中的cat - 86基因编码氯霉素乙酰转移酶（CAT），并在枯草芽孢杆菌中处于首次观察到内部芽孢的芽孢形成阶段（约T8期）时选择性表达。该基因在营养生长的细胞中不表达。当细胞在过量葡萄糖中生长时，cat - 86的表达和芽孢形成均被阻断。T8期cat - 86的表达是由于该基因的选择性转录，因为在营养生长的细胞中检测不到cat - 86 mRNA，但在芽孢形成的细胞中很容易检测到。来自芽孢形成细胞的cat - 86 mRNA的转录起始位点位于一个203个碱基对的限制性片段P1内，该片段位于pPL603上cat编码区的上游。从pPL603中删除P1会消除cat - 86与芽孢形成相关的表达。宿主芽孢形成基因，其功能是T8期cat - 86表达所绝对必需的，包括六个早期芽孢形成基因spo0和spoIIE。因此，pPL603提供了一个新的系统，其中已知的质粒连接基因的体内表达依赖于枯草芽孢杆菌中芽孢形成特异性的变化。
