Distinct roles of the N-terminal and C-terminal precursor domains in the biogenesis of the Bordetella pertussis filamentous hemagglutinin

作者：Geneviève Renauld‐Mongénie, Jocelyne Cornette, Nathalie Mielcarek, Franco Dante Menozzi, Camille Locht · 发表于：Journal of Bacteriology · 年份：1996 · DOI：10.1128/jb.178.4.1053-1060.1996 · 被引用次数：86 · 研究领域：Bacterial Infections and Vaccines、Bacterial Genetics and Biotechnology、RNA and protein synthesis mechanisms

The 220-kDa Bordetella pertussis filamentous hemagglutinin (FHA) is the major exported protein found in culture supernatants. The structural gene of FHA has a coding potential for a 367-kDa protein, and the mature form constitutes the N-terminal 60% of the 367-kDa precursor. The C-terminal domain of the precursor was found to be important for the high-level secretion of full-length FHA but not of truncated analogs (80 kDa or less). The secretion of full-length and truncated FHA polypeptides requires the presence of the approximately 100-amino-acid N-terminal domain and the outer membrane protein FhaC, homologous to the N-terminal domains of the Serratia marcescens and Proteus mirabilis hemolysins and their accessory proteins, respectively. By analogy to these hemolysins, it is likely that the N-terminal domain of the FHA precursor interacts, directly or indirectly, with the accessory protein during FHA biogenesis. However, immunogenicity and antigenicity studies suggest that the N-terminal domain of FHA is masked by its C-terminal domain and therefore should not be available for its interactions with FhaC. These observations suggest a model in which the C-terminal domain of the FHA precursor may play a role as an intramolecular chaperone to prevent premature folding of the protein. Both heparin binding and hemagglutination are expressed by the N-terminal half of FHA, indicating that this domain contains important functional regions of the molecule.