BB0324 and BB0028 are constituents of the Borrelia burgdorferi β-barrel assembly machine (BAM) complex

BMC Microbiology

Research Article

Darrin R Akins¹  Melisha R Kenedy¹  Tiffany R Lenhart²  Xiuli Yang³  Utpal Pal³ 

[1] Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 73104, Oklahoma City, OK, USA;Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, 73104, Oklahoma City, OK, USA;Department of Botany and Microbiology, University of Oklahoma, 73019, Norman, OK, USA;Department of Veterinary Medicine, University of Maryland, 20742, College Park, MD, USA;Virginia-Maryland Regional College of Veterinary Medicine, 20742, College Park, MD, USA;

关键词: Outer Membrane;    Borrelia Burgdorferi;    Signal Peptidase;    Sucrose Density Gradient Centrifugation;    Blue Native Page;   

DOI  :  10.1186/1471-2180-12-60

 received in 2011-11-30, accepted in 2012-04-20,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundSimilar to Gram-negative bacteria, the outer membrane (OM) of the pathogenic spirochete, Borrelia burgdorferi, contains integral OM-spanning proteins (OMPs), as well as membrane-anchored lipoproteins. Although the mechanism of OMP biogenesis is still not well-understood, recent studies have indicated that a heterooligomeric OM protein complex, known as BAM (β-barrel assembly machine) is required for proper assembly of OMPs into the bacterial OM. We previously identified and characterized the essential β-barrel OMP component of this complex in B. burgdorferi, which we determined to be a functional BamA ortholog.ResultsIn the current study, we report on the identification of two additional protein components of the B. burgdorferi BAM complex, which were identified as putative lipoproteins encoded by ORFs BB0324 and BB0028. Biochemical assays with a BamA-depleted B. burgdorferi strain indicate that BB0324 and BB0028 do not readily interact with the BAM complex without the presence of BamA, suggesting that the individual B. burgdorferi BAM components may associate only when forming a functional BAM complex. Cellular localization assays indicate that BB0324 and BB0028 are OM-associated subsurface lipoproteins, and in silico analyses indicate that BB0324 is a putative BamD ortholog.ConclusionsThe combined data suggest that the BAM complex of B. burgdorferi contains unique protein constituents which differ from those found in other proteobacterial BAM complexes. The novel findings now allow for the B. burgdorferi BAM complex to be further studied as a model system to better our understanding of spirochetal OM biogenesis in general.

【 授权许可】

Unknown   
© Lenhart 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.