Lin J W, Chen L M, Chen H Y, Weng S F
Institute of Biochemistry, National Chung Hsing University, Taichung, Taiwan, Republic of China.
Biochem Biophys Res Commun. 1998 Sep 18;250(2):462-5. doi: 10.1006/bbrc.1998.9325.
Nucleotide sequence of the regulatory region R&R* and the partial 5'-end of the cnf1 gene (GenBank Accession No. AF023157) of Vibrio fischeri ATCC 7744 has been determined, and the cytotoxic necrotizing factor 1 (CNF1) encoded by the cnf1 gene is deduced. Alignment and comparison of the cytotoxic necrotizing factor 1s of V. fischeri and E. coli show that they are homologous. Nucleotide sequence reveals that the cnf1 gene is closely linked to the lux regulon in genome; the gene order of the cnf1 gene and the lux regulon is <--cnf1-R&R*<--rrn-<--luxR-R&R-luxI-luxC-luxD -luxA-luxB-luxE-luxG-omega-->, whereas R&R is the regulatory region of the lux regulon, and R&R* is the regulatory region of the cnf1 gene; the sequence approximately 2 kb lay between the luxR gene of the lux regulon and the cnf1 gene is an rrn-like operon. It is unexpected to find the cnf1 gene in V. fischeri, since the CNF1 protein enables necrosis; the marine luminous bacterium V. fischeri is never to be identified as a pathogenic microbe. The cnf1 gene might be concerned with symbosis of the luminous bacteria and host fishes.
费氏弧菌ATCC 7744的调节区域R&R及cnf1基因部分5'端的核苷酸序列（基因库登录号：AF023157）已被测定，并推导了cnf1基因编码的细胞毒性坏死因子1（CNF1）。费氏弧菌和大肠杆菌的细胞毒性坏死因子1的比对和比较表明它们是同源的。核苷酸序列显示cnf1基因在基因组中与lux操纵子紧密相连；cnf1基因和lux操纵子的基因顺序为<--cnf1-R&R<--rrn-<--luxR-R&R-luxI-luxC-luxD -luxA-luxB-luxE-luxG-omega-->，其中R&R是lux操纵子的调节区域，R&R*是cnf1基因的调节区域；lux操纵子的luxR基因和cnf1基因之间大约2 kb的序列是一个类rrn操纵子。在费氏弧菌中发现cnf1基因是出乎意料的，因为CNF1蛋白会导致坏死；海洋发光细菌费氏弧菌从未被鉴定为致病微生物。cnf1基因可能与发光细菌和宿主鱼类的共生有关。
