Global regulation by gidA in Pseudomonas sytingae
Global regulation by gidA in Pseudomonas sytingae
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DOI：
10.1128/jb.184.8.2281-2286.2002
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发表时间：
2002-04-01
影响因子：
3.2
通讯作者：
Willis, DK
中科院分区：
文献类型：
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作者：
Kinscherf, TG;Willis, DK
对丁香假单胞菌B728a的两个毒力突变株的分析表明，Tn5插入位点位于gida开放阅读框(ORF)内。这些突变是多效性的，影响不同的表型特征，如脂多肽(丁香霉素和丁香肽)抗生素的产生、成群、荧光素的存在和毒力。破坏的gid4基因与染色体的定点重组导致了与转座子插入相同的表型模式。突变的表型通过一个质粒上的gid4 ORF恢复。在gacs和gacA突变体中，作为丁香霉素缺乏表型的拷贝数抑制因子saL4基因也被发现抑制了gida突变体的抗生素阴性表型，提示gida基因可能在saL4调控中起一定作用。记者对染色体saL4-lacZ翻译融合的研究证实，在gida突变背景下，saL4报告基因的表达下降了近5倍，同时丁香霉素生物合成报告融合基因syrB-lacZ的表达也同时下降。通过在质粒上提供完整的gida基因，可以恢复报告基因的野生型表达水平。通常被描述为参与细胞分裂的最近的证据表明，GIDA在调节翻译保真度方面发挥了作用，这表明了一种可能发生全球调控的机制。Gida基因基本上在细菌域和真核生物域中是普遍存在的，但在古生菌中没有对应的基因，这可能反映了前一个域和后一个域之间翻译机制的具体差异。
Analysis of two virulence mutants of Pseudomonas syringae B728a revealed that the Tn 5 sites of insertion were within the gidA open reading frame (ORF). These mutations were pleiotropic, affecting diverse phenotypic traits, such as lipodepsipeptide (syringomycin and syringopeptin) antibiotic production, swarming, presence of fluorescent pigment, and virulence. Site-specific recombination of a disrupted gid4 gene into the chromosome resulted in the same phenotypic pattern as transposon insertion. Mutant phenotypes were restored by the gid4 ORF on a plasmid. The saL4 gene, a copy number suppressor of the syringomycin-deficient phenotype in gacS and gacA mutants, was also found to suppress the antibiotic-negative phenotypes of gidA mutants, suggesting that gidA might play some role in saL4 regulation. Reporter studies with chromosomal saL4-lacZ translational fusions confirmed that saL4 reporter expression decreased approximately fivefold in a gidA mutant background, with a concurrent decrease in the expression of the syringomycin biosynthetic reporter fusion syrB-lacZ. Wild-type levels of reporter expression were restored by supplying an intact gidA gene on a plasmid. Often described as being involved in cell division, more recent evidence suggests a role for gidA in moderating translational fidelity, suggesting a mechanism by which global regulation might occur. The gidA gene is essentially universal in the domains Bacteria and Eucarya but has no counterparts in Archaea, probably reflecting specific differences in the translational machinery between the former and latter domains.