Borrelia burgdorferi BBA74, a Periplasmic Protein Associated with the Outer Membrane, Lacks Porin-Like Properties
| Autor: | Dionysios Liveris, Ira Schwartz, Vishwaroop Mulay, Justin D. Radolf, Daniel C. Desrosiers, Melissa J. Caimano |
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| Rok vydání: | 2007 |
| Předmět: |
Vesicle-associated membrane protein 8
Porins Periplasmic space Biology Enzymes and Proteins Microbiology Protein Structure Secondary Bacterial Proteins Membrane protein Biochemistry Porin Outer membrane efflux proteins Virulence-related outer membrane protein family Periplasmic Proteins Fluorescent Antibody Technique Indirect Bacterial outer membrane Molecular Biology Integral membrane protein Bacterial Outer Membrane Proteins |
| Zdroj: | Journal of Bacteriology. 189:2063-2068 |
| ISSN: | 1098-5530 0021-9193 |
| DOI: | 10.1128/jb.01239-06 |
| Popis: | The outer membrane of Borrelia burgdorferi , the causative agent of Lyme disease, contains very few integral membrane proteins, in contrast to other gram-negative bacteria. BBA74, a Borrelia burgdorferi plasmid-encoded protein, was proposed to be an integral outer membrane protein with putative porin function and designated as a 28-kDa outer membrane-spanning porin (Oms28). In this study, the biophysical properties of BBA74 and its subcellular localization were investigated. BBA74 is posttranslationally modified by signal peptidase I cleavage to a mature 25-kDa protein. The secondary structure of BBA74 as determined by circular dichroism spectroscopy consists of at least 78% α-helix with little β-sheet structure. BBA74 in intact B. burgdorferi cells was insensitive to proteinase K digestion, and indirect immunofluorescence microscopy showed that BBA74 was not exposed on the cell surface. Triton X-114 extraction of outer membrane vesicle preparations indicated that BBA74 is not an integral membrane protein. Taken together, the data indicate that BBA74 is a periplasmic, outer membrane-associated protein that lacks properties typically associated with porins. |
| Databáze: | OpenAIRE |
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