A conserved C-terminal 13-amino-acid motif of Gap1 is required for Gap1 function and necessary for the biogenesis of a serine-rich glycoprotein of Streptococcus parasanguinis.
A conserved C-terminal 13-amino-acid motif of Gap1 is required for Gap1 function and necessary for the biogenesis of a serine-rich glycoprotein of Streptococcus parasanguinis.
复制标题
Gap1 的保守 C 端 13 个氨基酸基序是 Gap1 功能所必需的，也是副血链球菌富含丝氨酸的糖蛋白的生物发生所必需的。
DOI：
10.1128/iai.00534-08
复制
发表时间：
2008
影响因子：
3.1
通讯作者：
Wu,Hui
中科院分区：
文献类型：
--
作者：
Zhou,Meixian;Peng,Zhixiang;Fives-Taylor,Paula;Wu,Hui
Adhesion ofStreptococcus parasanguinisto saliva-coated hydroxyapatite (SHA), an in vitro tooth model, is mediated by long peritrichous fimbriae. Fap1, a fimbria-associated serine-rich glycoprotein, is required for fimbrial assembly. Biogenesis of Fap1 is controlled by an 11-gene cluster that containsgly,nss,galT1and -2,secY2,gap1to -3,secA2, andgtf1and -2. We had previously isolated a collection of nine nonadherent mutants using random chemical mutagenesis approaches. These mutants fail to adhere to the in vitro tooth model and to form fimbriae. In this report, we further characterized these randomly selected nonadherent mutants and classified them into three distinct groups. Two groups of genes were previously implicated in Fap1 biogenesis. One group has a mutation in a glycosyltransferase gene,gtf1, that is essential for the first step of Fap1 glycosylation, whereas the other group has defects in thefap1structural gene. The third group mutant produces an incompletely glycosylated Fap1 and exhibits a mutant phenotype similar to that of a glycosylation-associated protein 1 (Gap1) mutant. Analysis of this new mutant revealed that a conserved C-terminal 13-amino-acid motif was missing in Gap1. Site-directed mutagenesis of a highly conserved amino acid tryptophan within this motif recapitulated the deletion phenotype, demonstrating the importance of the Gap1 C-terminal motif for Fap1 biogenesis. Furthermore, the C-terminal mutation does not affect Gap1-Gap3 protein-protein interaction, which has been shown to mediate Fap1 glycosylation, suggesting the C-terminal motif has a distinct function related to Fap1 biogenesis.
