Lipopolysaccharide biosynthesis-related genes are required for colony pigmentation of Porphyromonas gingivalis
Lipopolysaccharide biosynthesis-related genes are required for colony pigmentation of Porphyromonas gingivalis
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DOI：
10.1099/mic.0.025163-0
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发表时间：
2009-04-01
期刊：
影响因子：
2.8
通讯作者：
Yoshimura, Fuminobu
中科院分区：
文献类型：
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作者：
Sato, Keiko;Kido, Nobuo;Yoshimura, Fuminobu
牙周病细菌牙龈卟啉单胞菌在血琼脂平板上孵育时，由于细胞表面上μ-氧血红素二聚体的积累而形成色素菌落。牙龈蛋白酶-粘附素复合物负责从血红蛋白产生mu-oxo血红素二聚体。通过Tn 4351转座子诱变从牙龈卟啉单胞菌分离非色素突变体（Tn 6 -5、Tn 7 -1、Tn 7 -3和Tn 10 -4）[Hoover & Yoshimura（1994），FEMS Microbiol Lett 124，43-48]。在这项研究中，我们发现Tn 6 -5，Tn 7 -1和Tn 7 -3突变体携带Tn 4351 DNA在一个基因同源的ugdA基因编码UDP-葡萄糖6-脱氢酶，一个基因编码一个假定的组1家族糖基转移酶和一个基因同源的rfa基因编码ADP庚糖-LPS庚糖基转移酶，分别。Tn 10 -4突变体在与Tn 7 -1相同的位置携带Tn 4351 DNA。与Tn 7 -3突变体（rfa）的细胞相关的牙龈蛋白酶活性非常弱，而在培养上清液中检测到牙龈蛋白酶活性。免疫印迹和质谱分析还显示，牙龈卟啉菌蛋白酶，包括其前体形式，存在于培养上清液中。rfa缺失突变体的脂多糖（LPS）部分未显示出通常在野生型牙龈卟啉单胞菌的LPS中观察到的梯状模式。重组嵌合体牙龈菌蛋白酶能够以剂量依赖性方式与野生型牙龈卟啉单胞菌的LPS部分结合。这些结果表明，rfa基因产物与LPS和/或细胞表面多糖的生物合成有关，这些多糖可以作为牙龈卟啉菌蛋白酶-粘附素复合物的锚定物。
The periodontopathic bacterium Porphyromonas gingivalis forms pigmented colonies when incubated on blood agar plates as a result of accumulation of mu-oxo haem dimer on the cell surface. Gingipain-adhesin complexes are responsible for production of mu-oxo haem dimer from haemoglobin. Non-pigmented mutants (Tn6-5, Tn7-1, Tn7-3 and Tn10-4) were isolated from P. gingivalis by Tn4351 transposon mutagenesis [Hoover & Yoshimura (1994), FEMS Microbiol Lett 124, 43-48]. In this study, we found that the Tn6-5, Tn7-1 and Tn7-3 mutants carried Tn4351 DNA in a gene homologous to the ugdA gene encoding UDP-glucose 6-dehydrogenase, a gene encoding a putative group 1 family glycosyltransferase and a gene homologous to the rfa gene encoding ADP heptose-LPS heptosyltransferase, respectively. The Tn10-4 mutant carried Tn4351 DNA at the same position as that for Tn7-1. Gingipain activities associated with cells of the Tn7-3 mutant (rfa) were very weak, whereas gingipain activities were detected in the culture supernatants. Immunoblot and mass spectrometry analyses also revealed that gingipains, including their precursor forms, were present in the culture supernatants. A lipopolysaccharide (LPS) fraction of the rfa deletion mutant did not show the ladder pattern that was usually seen for the LPS of the wild-type P. gingivalis. A recombinant chimera gingipain was able to bind to an LPS fraction of the wild-type P. gingivalis in a dose-dependent manner. These results suggest that the rfa gene product is associated with biosynthesis of LPS and/or cell-surface polysaccharides that can function as an anchorage for gingipain-adhesin complexes.