Mutations in Flavobacterium johnsoniae sprE Result in Defects in Gliding Motility and Protein Secretion
Mutations in Flavobacterium johnsoniae sprE Result in Defects in Gliding Motility and Protein Secretion
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DOI：
10.1128/jb.05480-11
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发表时间：
2011-10-01
影响因子：
3.2
通讯作者：
McBride, Mark J.
中科院分区：
文献类型：
--
作者：
Rhodes, Ryan G.;Samarasam, Mudiarasan Napoleon;McBride, Mark J.
滑行细菌约氏黄杆菌的细胞在表面上快速移动。转座子诱变用于鉴定参与滑行的sprE。sprE突变导致琼脂上形成非扩展菌落。湿标本中的sprE突变细胞几乎完全缺乏在玻璃上的附着和运动，但一小部分细胞表现出轻微的运动，这表明运动机制并未完全被破坏。SprE是一种预测的具有三肽重复结构域的脂蛋白。SprE在序列上与牙龈卟啉单胞菌PorW相似，这是分泌牙龈卟啉菌蛋白酶毒力因子所必需的。F的破坏。johnsoniae sprE导致胞外几丁质酶活性降低和细胞表面运动蛋白SprB分泌减少。滑行机制的细胞表面成分（例如SprB）分泌减少可能是滑行缺陷的原因。在拟杆菌门的许多滑动和非滑动成员中发现了sprE的直系同源物，这表明类似的蛋白质分泌系统在这个庞大而多样的细菌群中很常见。
Cells of the gliding bacterium Flavobacterium johnsoniae move rapidly over surfaces. Transposon mutagenesis was used to identify sprE, which is involved in gliding. Mutations in sprE resulted in the formation of nonspreading colonies on agar. sprE mutant cells in wet mounts were almost completely deficient in attachment to and movement on glass, but a small percentage of cells exhibited slight movements, indicating that the motility machinery was not completely disrupted. SprE is a predicted lipoprotein with a tetratricopeptide repeat domain. SprE is similar in sequence to Porphyromonas gingivalis PorW, which is required for secretion of gingipain protease virulence factors. Disruption of F. johnsoniae sprE resulted in decreased extracellular chitinase activity and decreased secretion of the cell surface motility protein SprB. Reduced secretion of cell surface components of the gliding machinery, such as SprB, may account for the defects in gliding. Orthologs of sprE are found in many gliding and nongliding members of the phylum Bacteroidetes, suggesting that similar protein secretion systems are common among members of this large and diverse group of bacteria.