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V. fishcheri lux regulon luxR gene 下游 3,565 bp 之 DNA 經定序分
析，得知此 DNA 片段，具有 RNA-like gene cluster、ufo1 gene、
origin-like sequence 與 cnf1 gene，與 lux regulon 之排列序列為
----cnf1-ori-like sequence-ufo1-RNA-like gene cluster-R&R'-luxR-
R&R-luxI-luxC-luxD-luxA-luxB-luxE----。其中 cnf1 為主導
cytotoxic necrotizing factor 1 基因；ufo1 為一未鑑定之基因；而
RNA-like gene cluster 包括一 rRNA-like gene 與數個 tRNA-like
genes；另存在一 origin-like sequence。此等基因顯然受 lux regulon
主調節區域 R&R (regulatory region) 的調控；之外，其內含調節區域
R&R'，則具有 terminator-like block 之功能，可弱化轉錄，減少其後
續基因之表現，亦具有可能為輔助啟動子 (intern promoter) 之序列，
可能為次調節 (sub-regulation) 系統，以調控基因表現。有關 lux
regulon 的調控，除了主調節區域 R&R 受 LuxR-AI、cAMP-CRP 的調控之
外，內含於 lux regulon 之次調節機制 (sub-regulation)，包括 R&R'
、terminator-like block、intern promoter、potential hairpin
loops 等，皆參與 lux regulon 基因的調控。實驗結果肯定次調節機制
(sub-regulation) 存在於 lux regulon；此等 sub-regulaton signals
，包括 terminator-like block 與可能之輔助啟動子 (intern
promoter) 存在於 luxC gene 內與 luxD gene 5' 端之前段。另外存在
於 luxB gene 之後、luxE gene 之前的 potential hairpin loop Wo''
則不具明顯之次調節機制。但此類似之 potential hairpin loop 亦存在
於 V. harveyi 與 P. leiognathi，皆具有弱化轉錄以調控螢光表現的作
用。結果顯示 lux regulon/operon 中確實存在 sub-regulation 次調節
機制以調控螢光表現。
The 3,565 bp DNA sequence downstream of the luxR gene in V.
fischeri lux regulon has been determined, which contains RNA-
like gene cluster, ufo1 gene, origin-like sequence, and cnf1
gene. Sequence analysis elucidates that there are several genes
resided in the DNA fragment: the cnf1 gene encodes cytotoxic
necrotizing factor 1; the ufo1 gene is not identified yet; the
RNA-like gene cluster contains a rRNA-like gene and several
tRNA-like genes; and an origin-like sequence is illustrated. The
gene order of these genes and the lux regulon is <--cnf1-ori-
like sequence-ufo1-RNA-like gene cluster-R&R'-luxR-R&R-luxI-
luxC-luxD-luxA-luxB-luxE----; whereas the regulatory region R&R
is the domain regulation for the lux regulon, and the regulatory
region R&R' contained terminator-like block is the sub-
regulation for the lux regulon. The regulatory region R&R'
contains an intern promoter, which enables to reduce
transcription and repress the gene expression of the genes
linked to the luxR gene, might function for sub-regulation. The
regulation of the lux regulon is not only under regulation by
the regulatory region R&R, which regulated by LuxR-AI and cAMP-
CRP, but also under sub-regulation by the regulatory region R&
R', terminator-like block, intern promoter, and potential
hairpin loop resided in the lux regulon. The terminator-like
block and intern promoter bet-ween the luxC gene and 5'-end of
the luxD gene is identified as sub-regulation signals. The
potential hairpin loop Wo'', which resided in the 3'-end of the
luxB gene, does not function for sub-regulation; but the similar
potential hairpin loops resided in the lux operons of V. harveyi
and P. leiognathi enable to deduce transcription. The results
elicits that the sub-regulation indeed is functioned for gene
expression and regulation of bioluminescence.
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