A mutation in Flavobacterium psychrophilum tlpB inhibits gliding motility and induces biofilm formation
A mutation in Flavobacterium psychrophilum tlpB inhibits gliding motility and induces biofilm formation
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DOI：
10.1128/aem.00128-06
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发表时间：
2006-06-01
影响因子：
4.4
通讯作者：
Guijarro, J. A.
中科院分区：
文献类型：
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作者：
Alvarez, B.;Secades, P.;Guijarro, J. A.
嗜冷黄杆菌（Flavobacterium psychrophilum）是一种嗜冷的鱼类病原性细菌，属于噬细胞黄杆菌类杆菌（Cytophaga-Flavobacterium-Bacteroides）类群。Tn 4351诱导的突变体缺乏滑行运动，铁耗尽的媒体上的增长，和细胞外蛋白水解活性进行了分离。这些突变体中的一些仅在这些特征中的一个中受到影响，而另一些在两个或更多个中具有缺陷。进一步研究了缺乏所有这些特性的突变体FP 523。FP 523在tlpB（巯基氧化还原酶样蛋白基因）中具有Tn 4351插入，该基因编码41.4-kDa蛋白质，该蛋白质的序列与具有已知功能的蛋白质的序列没有表现出高水平的相似性。TIpB具有两个结构域; N-末端结构域具有五个跨膜区，而C-末端结构域具有Cys-X-X-Cys基序和硫醇：二硫键氧化还原酶特征的其它保守基序。周质蛋白的巯基的定量分析表明，TIpB是需要减少这些基团。tlpB基因是fpt（F.嗜冷菌硫醇氧化还原酶）操纵子，其含有另外两个基因tlpA和tpiA，其分别编码硫醇：二硫键氧化还原酶和磷酸丙糖异构酶。FP 523表现出增强的生物膜形成和降低的毒力和细胞毒性。与tlpB位点互补恢复了野生型表型。滑动运动性和生物膜形成似乎是拮抗性质，这两者都受到TIpB的影响。
Flavobacterium psychrophilum is a psychrotrophic, fish-pathogenic bacterium belonging to the Cytophaga-Flavobacterium-Bacteroides group. Tn4351-induced mutants deficient in gliding motility, growth on iron-depleted media, and extracellular proteolytic activity were isolated. Some of these mutants were affected in only one of these characteristics, whereas others had defects in two or more. FP523, a mutant deficient in all of these properties, was studied further. FP523 had a Tn4351 insertion in tlpB (thiol oxidoreductase-like protein gene), which encodes a 41.4-kDa protein whose sequence does not exhibit high levels of similar to the sequences of proteins having known functions. TIpB has two domains; the N-terminal domains has five transmembrane regions, whereas the C-terminal domains has the Cys-X-X-Cys motif and other conserved motifs characteristic of thiol:disulfide oxidoreductases. Quantitative analysis of the thiol groups of periplasmic proteins revealed that TIpB is required for reduction of these groups. The tlpB gene is part of the fpt (F. psychrophilum thiol oxidoreductase) operon that contains two other genes, tlpA and tpiA, which encode a thiol:disulfide oxidoreductase and a triosephosphate isomerase, respectively. FP523 exhibited enhanced biofilm formation and decreased virulence and cytotoxicity. Complementation with the tlpB loci restored the wild-type phenotype. Gliding motility and biofilm formation appear to be antagonistic properties, which are both affected by TIpB.