Physical mapping and complementation analysis of transposon Tn5 mutations in Caulobacter crescentus: organization of transcriptional units in the hook gene cluster.
Physical mapping and complementation analysis of transposon Tn5 mutations in Caulobacter crescentus: organization of transcriptional units in the hook gene cluster.
复制标题
新月柄杆菌转座子 Tn5 突变的物理作图和互补分析：钩子基因簇中转录单位的组织。
DOI：
10.1128/jb.158.3.897-904.1984
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发表时间：
1984
影响因子：
3.2
通讯作者：
Newton,A
中科院分区：
文献类型：
--
作者：
Ohta,N;Swanson,E;Ely,B;Newton,A
使用来自新月柄杆菌的钩蛋白基因区的克隆DNA（Ohta等人，Proc. Natl. Acad. Sci. U.S.A. 79：4863-4867，1982），我们已经鉴定了19个Tn 5诱导的插入突变和2个自发插入突变并将其物理定位到染色体的该区域。这些非运动突变体定义了一个主要的弗拉基因簇，其覆盖了染色体上的大约17个组氨酸酶（hook基因簇）。使用来自广泛宿主范围质粒pRK 290中亚克隆的区域的DNA片段对突变体进行互补分析表明，这些弗拉基因被组织成至少5个转录单位（I至V）。转录单位II除了hook蛋白基因外还含有至少一个基因，这使得它成为C. crescentus。这组突变体的钩蛋白基因和遗传上不连锁的鞭毛蛋白A和B基因的表达也进一步阐明了鞭毛基因的分级调控。我们发现钩蛋白基因（flaK）的自发插入突变体（SC 511）不产生鞭毛蛋白A或B，并且钩蛋白基因下游的基因是表达钩蛋白操纵子和鞭毛蛋白A和B基因所必需的反式。因此，重叠和互补结果将flaK、flaJ、flaN和flaO（R. C.约翰逊和B。伊利，细菌学杂志。137：627-634，1979），鉴定了至少三个新基因（flbD、flbG和flbF），并表明该簇可能含有几个另外的尚未鉴定的弗拉基因。
Using the cloned DNA from the hook protein gene region of Caulobacter crescentus ( Ohta et al., Proc. Natl. Acad. Sci. U.S.A. 79:4863-4867, 1982), we have identified and physically mapped 19 Tn5-induced and 2 spontaneous insertion mutations to this region of the chromosome. These nonmotile mutants define a major cluster of fla genes that covers approximately 17 kilobases on the chromosome (hook gene cluster). Complementation analysis of the mutants using DNA fragments from the region subcloned in the broad host range plasmid pRK290 has shown that these fla genes are organized into at least five transcriptional units (I to V). Transcriptional unit II contains at least one gene in addition to the hook protein gene, which makes this the first operon described in C. crescentus. Expression of the hook protein gene and the genetically unlinked flagellin A and B genes by this set of mutants also furnishes additional insights into the hierarchial regulation of flagellar genes. We have found that the spontaneous insertion mutant ( SC511 ) of the hook protein gene ( flaK ) makes no flagellin A or B and that genes downstream from the hook protein gene are required in trans for expression of the hook protein operon and the flagellin A and B genes. Recombination and complementation results thus place flaK , flaJ , flaN , and flaO (R. C. Johnson and B. Ely , J. Bacteriol . 137:627-634, 1979) in the hook gene cluster, identify at least three new genes ( flbD , flbG , and flbF ), and suggest that this cluster may contain several additional, as yet unidentified, fla genes.