INACTIVATION OF THE GENE ENCODING SURFACE PROTEIN SSPA IN STREPTOCOCCUS-GORDONII DL1 AFFECTS CELL-INTERACTIONS WITH HUMAN SALIVARY AGGLUTININ AND ORAL ACTINOMYCES
INACTIVATION OF THE GENE ENCODING SURFACE PROTEIN SSPA IN STREPTOCOCCUS-GORDONII DL1 AFFECTS CELL-INTERACTIONS WITH HUMAN SALIVARY AGGLUTININ AND ORAL ACTINOMYCES
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DOI：
10.1128/iai.61.8.3199-3208.1993
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发表时间：
1993-08-01
影响因子：
3.1
通讯作者：
TANNOCK, GW
中科院分区：
文献类型：
--
作者：
JENKINSON, HF;TERRY, SD;TANNOCK, GW
口腔细菌戈登链球菌M5中的细胞表面蛋白SSP-5以Ca 2+依赖性反应结合人唾液凝集素（D. R. Demuth，E. E. Golub和D. Malamud，J.Biol.Chem.265：7120-7126，1990）。编码S.戈登氏菌DL 1（查利斯）在聚合酶链反应扩增基因组DNA后分离。SspA基因在S.通过红霉素抗性（Em（r））决定簇ermAM在链球菌染色体上的同源重组使戈登氏菌DL 1插入失活。SspA多肽（表观分子量，210 kDa）在来自野生型菌株DL 1的原生质球提取物和细胞外培养基蛋白的Western印迹（免疫印迹）上检测到，但在Em（r）突变体中不存在。一种SspA突变体（指定为OB 220）在全唾液或腮腺唾液的聚集速率或程度上没有改变，但在纯化的唾液凝集素存在下显示出聚集减少。突变细菌的粘附能力与整个或腮腺唾液包被的羟基磷灰石珠未受影响，细胞表面疏水性不变。然而，SspA-菌株OB 220在结合唾液凝集素和结合六种内氏放线菌菌株方面是缺陷的。因此，SspA多肽在S. Gordonii与链球菌细胞的凝集素依赖性和凝集素非依赖性聚集和粘附反应有关。
Cell surface protein SSP-5 in the oral bacterium Streptococcus gordonii M5 binds human salivary agglutinin in a Ca2+-dependent reaction (D. R. Demuth, E. E. Golub, and D. Malamud, J. Biol. Chem. 265:7120-7126, 1990). The region of the gene encoding an N-terminal segment of a related polypeptide (SspA) in S. gordonii DL1 (Challis) was isolated following polymerase chain reaction amplification of genomic DNA. The sspA gene in S. gordonii DL1 was insertionally inactivated by homologous recombination of the erythromycin resistance (Em(r)) determinant ermAM onto the streptococcal chromosome. The SspA polypeptide (apparent molecular mass, 210 kDa) was detected on Western blots (immunoblots) of spheroplast extracts and extracellular culture medium proteins from wild-type strain DL1 but was absent from Em(r) mutants. One SspA- mutant (designated OB220) was not altered in rate or extent of aggregation by whole saliva or parotid saliva but showed reduced aggregation in the presence of purified salivary agglutinin. Mutant bacteria were unaffected in their ability to adhere to hydroxylapatite beads coated with whole or parotid saliva and were unaltered in cell surface hydrophobicity. However, the SspA- strain OB220 was deficient in binding salivary agglutinin and in binding to six strains of Actinomyces naeslundii. Therefore, expression of SspA polypeptide in S. gordonii is associated with both agglutinin-dependent and agglutinin-independent aggregation and adherence reactions of streptococcal cells.