Absence of long-range diffusion of OmpA in E. coliis not caused by its peptidoglycan binding domain

BMC Microbiology

Research Article

Marileen Dogterom¹  Tanneke den Blaauwen²  Gertjan S Verhoeven³ 

[1] FOM Institute AMOLF, Science Park 104, 1098, Amsterdam, XG, The Netherlands;Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098, Amsterdam, XH, The Netherlands;Bacterial Cell Biology, Swammerdam Institute for Life Sciences, University of Amsterdam, Sciencepark 904, 1098, Amsterdam, XH, The Netherlands;Molecular Cytology, Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098, Amsterdam, XH, The Netherlands;FOM Institute AMOLF, Science Park 104, 1098, Amsterdam, XG, The Netherlands;

关键词: Bacterial cell wall;    Peptidoglycan;    Outer membrane;    Diffusion;    FRAP;    Cell membrane;    OmpA;   

DOI  :  10.1186/1471-2180-13-66

 received in 2012-12-23, accepted in 2013-03-18,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundIt is widely believed that integral outer membrane (OM) proteins in bacteria are able to diffuse laterally in the OM. However, stable, immobile proteins have been identified in the OM of Escherichia coli. In explaining the observations, a hypothesized interaction of the immobilized OM proteins with the underlying peptidoglycan (PG) cell wall played a prominent role.ResultsOmpA is an abundant outer membrane protein in E. coli containing a PG-binding domain. We use FRAP to investigate whether OmpA is able to diffuse laterally over long-range (> ~100 nm) distances in the OM. First, we show that OmpA, containing a PG binding domain, does not exhibit long-range lateral diffusion in the OM. Then, to test whether PG interaction was required for this immobilization, we genetically removed the PG binding domain and repeated the FRAP experiment. To our surprise, this did not increase the mobility of the protein in the OM.ConclusionsOmpA exhibits an absence of long-range (> ~100 nm) diffusion in the OM that is not caused by its PG binding domain. Therefore, other mechanisms are needed to explain this observation, such as the presence of physical barriers in the OM, or strong interactions with other elements in the cell envelope.

【 授权许可】

Unknown   
© Verhoeven et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.