Arginine biosynthesis and regulation in Lactobacillus plantarum: The carA gene and the argCJBDF cluster are divergently transcribed
Arginine biosynthesis and regulation in Lactobacillus plantarum: The carA gene and the argCJBDF cluster are divergently transcribed
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DOI：
10.1128/jb.179.8.2697-2706.1997
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发表时间：
1997-04-01
影响因子：
3.2
通讯作者：
Hubert, JC
中科院分区：
文献类型：
--
作者：
Bringel, F;Frey, L;Hubert, JC
从植物乳杆菌CCM 1904 (ATCC 8014) DNA片段中克隆了一组瓜氨酸生物合成基因，并对其进行了测序，该片段与枯草芽孢杆菌argF突变互补。基因序列为carA- argcjbdf， carA与arg簇的转录方式不同，尽管其他革兰氏阳性菌也有类似的arg簇，但carA的这种排列方式迄今为止是前所未有的。在arg簇的下游，发现了两个功能未知的开放阅读框（ORF7和ORF8）。对10.5 kb克隆DNA片段的序列分析表明，argF来自编码L-(+)-乳酸脱氢酶的IdhL基因的3.5 kb。对来自不同生物的31种鸟氨酸氨基甲酰转移酶（OTCases）的氨基酸序列聚类关系进行了树状图分析，发现了两个原核类群：一个与L. plantarum的ArgF有关，一个与B. subtilis的ArgF有关，它们是同源的。这种差异在体内没有观察到，因为没有OTCase活性的植物乳杆菌argF突变体（AM 1215）被植物乳杆菌和枯草芽孢杆菌的argF基因所补充。当植物乳杆菌在饱和量的精氨酸或瓜氨酸存在下生长时，没有检测到OTCase活性。在植物L. plantarum中，精氨酸可能通过11个与大肠杆菌ARG盒一致的DNA基序来抑制瓜氨酸生物合成基因，这些基序在大多数情况下相隔11 bp，对应于DNA螺旋旋转。carA和argCJBDF基因是分化转录的，它们的推定启动子相距6 bp，并且部分被推定ARG盒重叠，表明协同转录调控。
A cluster of citrulline biosynthetic genes has been cloned and sequenced from a fragment of Lactobacillus plantarum CCM 1904 (ATCC 8014) DNA isolated as complementing a Bacillus subtilis argF mutation. The gene order was carA-argCJBDF, with carA transcribed divergently from the arg cluster, Although other gram-positive bacteria show similar arg clusters, this arrangement for carA is thus far unprecedented, Downstream from the arg cluster, two open reading frames (ORF7 and ORF8) having unknown functions were found. Sequence analysis of the end of a 10.5-kb cloned DNA fragment showed that argF was 3.5 kb from the IdhL gene coding for L-(+)-lactate dehydrogenase. A tree representation of amino acid sequence clustering relationships of 31 ornithine carbamoyltransferases (OTCases) from various organisms revealed two prokaryotic groups: one with ArgF of L. plantarum and one with ArgF of B. subtilis, which are paralogous. This divergence was not observed in vivo because an L. plantarum argF mutant (AM 1215) harboring no OTCase activity was complemented by the argF genes of L. plantarum and B., subtilis. No OTCase activity was detectable when L. plantarum was grown in the presence of saturating amounts of arginine or citrulline. Arginine may repress the citrulline biosynthetic genes in L. plantarum by using 11 identified DNA motifs which resemble the Escherichia coli ARG box consensus and which are in most cases separated by multiples of 11 bp, corresponding to a DNA helical turn, The carA and argCJBDF genes are divergently transcribed, Their putative promoters are 6 bp apart and are partially overlapped by putative ARG boxes, suggesting concerted transcription regulation.