Analysis of the cell surface layer ultrastructure of the oral pathogen Tannerella forsythia

Autor: Gerhard Sekot, Gerald Posch, Harald F. Mayer, Peter Hinterdorfer, Christina Schäffer, Yoo Jin Oh, Sonja Zayni, Dietmar Pum, Paul Messner
Rok vydání: 2012
Předmět:
Zdroj: Archives of Microbiology
ISSN: 1432-072X
0302-8933
DOI: 10.1007/s00203-012-0792-3
Popis: The Gram-negative oral pathogen Tannerella forsythia is decorated with a 2D crystalline surface (S-) layer, with two different S-layer glycoprotein species being present. Prompted by the predicted virulence potential of the S-layer, this study focused on the analysis of the arrangement of the individual S-layer glycoproteins by a combination of microscopic, genetic, and biochemical analyses. The two S-layer genes are transcribed into mRNA and expressed into protein in equal amounts. The S-layer was investigated on intact bacterial cells by transmission electron microscopy, by immune fluorescence microscopy, and by atomic force microscopy. The analyses of wild-type cells revealed a distinct square S-layer lattice with an overall lattice constant of 10.1 ± 0.7 nm. In contrast, a blurred lattice with a lattice constant of 9.0 nm was found on S-layer single-mutant cells. This together with in vitro self-assembly studies using purified (glyco)protein species indicated their increased structural flexibility after self-assembly and/or impaired self-assembly capability. In conjunction with TEM analyses of thin-sectioned cells, this study demonstrates the unusual case that two S-layer glycoproteins are co-assembled into a single S-layer. Additionally, flagella and pilus-like structures were observed on T. forsythia cells, which might impact the pathogenicity of this bacterium.
Databáze: OpenAIRE
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