THE ROLE OF TYPE V SECRETION AUTOTRANSPORTERS

• Author(s): Igo, Michele; Kirkpatrick, Bruce; Matsumoto, Ayumi;
• Abstract: Autotransporters are multi-domain proteins that are responsible for secreting a single specific polypeptide (the passenger domain) across the outer membrane of Gram-negative bacteria. At last years Symposium, we reported our studies characterizing a strain containing a kanamycin insertion in the putative autotransporter protein PD0528. Here, we report the results of our complementation analysis with the PD0528::Km mutant strain. Reintroduction of the wild-type PD0528 gene into the mutant strain restored the presence of PD0528 and a number of other proteins to the Xf outer membrane. However, reintroduction of PD0528 did not correct the phenotypic properties of the mutant strain or restore a wild-type phenotype. This would suggest that a second mutation(s) was acquired during the initial construction of the PD0528::Km mutant strain. Therefore, we decided to regenerate a null mutation in PD0528 using a variety of different strategies. None of these strategies were successful, which suggests that PD0528 might be an essential gene. During the course of these experiments, we also discovered a technical problem with the selection method we used for gene replacement in Xf. Although this may be a problem unique to our laboratory, we decided to include these data in case other researchers in the field are running into similar technical difficulties.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium