Organization and expression of a gene cluster involved in the biosynthesis of the lantibiotic lactocin S
Organization and expression of a gene cluster involved in the biosynthesis of the lantibiotic lactocin S
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参与羊毛硫抗生素乳素 S 生物合成的基因簇的组织和表达
DOI：
10.1007/s004380050371
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
I. Nes
中科院分区：
文献类型：
--
作者：
M. Skaugen;C. Abildgaard;I. Nes
摘要对清酒乳杆菌质粒pCIM 1的8.8kb序列进行了测定，发现其lasA下游有8个紧密聚集的开放阅读框（ORF），编码前乳素S。转录分析表明，这些基因表达为操纵子，转录起始于lasA上游，终止于第9个ORF的3′端。lasA也由两个大小相差约90个核苷酸的小RNA（RNAi和RNAII）表示，引物延伸实验证明了5′端的相应差异。RNA Ⅰ和RNA Ⅱ的3′末端都有一个回文序列，该序列在控制las操纵子的表达中具有双重调控功能，既作为lasA特异性转录物的3′-5′外切核酸酶降解的屏障，又作为限制下游基因表达的“泄漏”转录终止子。在las操纵子中的三个基因在其他lantibiotic系统中具有可识别的对应物：lasM可能参与前肽修饰，lasT，其编码ATP依赖性转运蛋白，可能参与乳蛋白S的分泌，而lasP指定枯草杆菌蛋白酶型丝氨酸蛋白酶，其可能是乳蛋白S前导肽酶。通过驻留转座因子IS 1163插入lasT或lasM的突变废除了乳蛋白S的产生。las操纵子中的其余五个ORF显然是独特的，并且它们相对于乳蛋白S表型的意义目前尚不清楚。
Abstract Some 8.8 kb of the Lactobacillus sake plasmid pCIM1 was sequenced, revealing eight tightly clustered open reading frames (ORFs) downstream from lasA, which encodes pre-lactocin S. Transcription analyses demonstrated that the genes are expressed as an operon, with transcription initiating upstream of lasA and terminating immediately 3′ to the ninth ORF · lasA is also represented by two small RNAs (RNAI and RNAII) which differ in size by approximately 90 nucleotides, and primer extension experiments demonstrated a corresponding difference in the 5′ termini. A palindromie sequence constitutes the 3′ terminus of both RNAI and RNAII, and we propose that this sequence has a dual regulatory function in controlling the expression of las operon, acting both as a barrier to 3′–5′ exonuclease degradation of the lasA-specific transcript(s), and as a “leaky” transcriptional terminator which limits the expression of down-stream genes. Three of the genes in the las operon have identifiable counterparts in other lantibiotic systems: lasM is likely to be involved in prepeptide modification, lasT, which encodes an ATP-dependent transport protein, is probably involved in the secretion of lactocin S, while lasP specifies a subtilisin-type serine protease which may be the lactocin S leader peptidase. Insertional mutation of either lasT or lasM by the resident transposable element IS1163 abolishes lactocin S production. The remaining five ORFs in the las operon are apparently unique, and their significance with respect to the lactocin S phenotype is presently not known.
影响因子：
--
作者：
G. Pfeifer;A. Riggs
通讯作者：
G. Pfeifer;A. Riggs
大肠杆菌的一种静止期蛋白，影响 trp 阻遏蛋白与操纵基因 DNA 之间的关联模式。
DOI：
10.1073/pnas.90.12.5796
发表时间：
1993
影响因子：
11.1
作者：
Yang,W;Ni,L;Somerville,RL
通讯作者：
Somerville,RL
使用小量制备质粒 DNA 通过 Sequenase 对双链模板进行测序。
影响因子：
2.7
作者：
Kraft,R;Tardiff,J;Krauter,KS;Leinwand,LA
通讯作者：
Leinwand,LA