PHB granules are attached to the nucleoid via PhaM in Ralstonia eutropha

BMC Microbiology

Research Article

Stephan Nussberger¹  Andreas Wahl²  Nora Schuth²  Dieter Jendrossek²  Daniel Pfeiffer² 

[1] Biophysics Department, Institute of Biology, University of Stuttgart, Pfaffenwaldring 57, 70550, Stuttgart, Germany;Institute of Microbiology, University of Stuttgart, Allmandring 31, 70550, Stuttgart, Germany;

关键词: Poly(3-hydroxybutyrate) (PHB);    Polyhydroxyalkanoate (PHA);    PHB granule formation;    Storage metabolism;    PhaM;    Biodegradable polymer;   

DOI  :  10.1186/1471-2180-12-262

 received in 2012-09-06, accepted in 2012-11-09,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundPoly(3-hydroxybutyrate) (PHB) granules are important storage compounds of carbon and energy in many prokaryotes which allow survival of the cells in the absence of suitable carbon sources. Formation and subcellular localization of PHB granules was previously assumed to occur randomly in the cytoplasm of PHB accumulating bacteria. However, contradictionary results on subcellular localization of PHB granules in Ralstonia eutropha were published, recently.ResultsHere, we provide evidence by transmission electron microscopy that PHB granules are localized in close contact to the nucleoid region in R. eutropha during growth on nutrient broth. Binding of PHB granules to the nucleoid is mediated by PhaM, a PHB granule associated protein with phasin-like properties that is also able to bind to DNA and to phasin PhaP5. Over-expression of PhaM resulted in formation of many small PHB granules that were always attached to the nucleoid region. In contrast, PHB granules of ∆phaM strains became very large and distribution of granules to daughter cells was impaired. Association of PHB granules to the nucleoid region was prevented by over-expression of PhaP5 and clusters of several PHB granules were mainly localized near the cell poles.ConclusionSubcellular localization of PHB granules is controlled in R. eutropha and depends on the presence and concentrations of at least two PHB granule associated proteins, PhaM and PhaP5.

【 授权许可】

Unknown   
© Wahl et al.; licensee BioMed Central Ltd. 2012. 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.