Identification of a novel two-partner secretion locus in Moraxella catarrhalis.
Identification of a novel two-partner secretion locus in Moraxella catarrhalis.
复制标题
卡他莫拉氏菌中新型两伙伴分泌位点的鉴定。
DOI：
10.1128/iai.00396-07
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发表时间：
2007
影响因子：
3.1
通讯作者：
Campagnari,AnthonyA
中科院分区：
文献类型：
--
作者：
Plamondon,Pascale;Luke,NicoleR;Campagnari,AnthonyA
AlthoughMoraxella catarrhaliscontinues to be a significant cause of disease in both children and adults, the steps involved in pathogenesis remain poorly understood. We have identified three open reading frames in theM. catarrhalisgenome that encode homologues of the two-partner secretion system (TPS). The sequencedM. catarrhalishemagglutinin-like locus of strain 7169 has a unique gene organization composed in the order ofmchA1,mchB, andmchA2, wheremchA1is divergent. MchA1 and MchA2 are 74% identical at the amino acid level and diverge only in the C-terminal regions. The TPS motif identified in the common N-terminal regions of MchA1 and MchA2 was found to be homologous to the filamentous hemagglutinin ofBordetella pertussis, and MchB has homology to other TpsB transporters. The presence of MchA1 and MchA2 in outer membrane protein preparations and concentrated culture supernatants (CCSs) of strain 7169 was confirmed by immunoblotting using specific antisera. Nanoscale liquid chromatography-tandem mass spectrometry peptide sequencing of the antibody-reactive bands from the CCSs was performed and demonstrated that 13 different peptides mapped to identical regions of MchA1 and MchA2. Quantitative adherence assays revealed a decrease of binding to primary normal human bronchial epithelial cells by themchmutants 7169mchB and 7169mchA1A2B compared to that by the wild-type strain. These studies show that MchA1, MchA2, and MchB are components of a novel TPS identified inM. catarrhalisand suggest that these proteins may be involved in colonization.
