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Rūmnieks J, Füzik T, Tārs K. Structure of the Borrelia Bacteriophage φBB1 Procapsid. J Mol Biol 2023; 435:168323. [PMID: 37866476 DOI: 10.1016/j.jmb.2023.168323] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 10/12/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
Bacteriophages of Borrelia burgdorferi are a biologically important but under-investigated feature of the Lyme disease-causing spirochete. No virulent borrelial viruses have been identified, but all B. burgdorferi isolates carry a prophage φBB1 as resident circular plasmids. Like its host, the φBB1 phage is quite distinctive and shares little sequence similarity with other known bacteriophages. We expressed φBB1 head morphogenesis proteins in Escherichia coli which resulted in assembly of homogeneous prolate procapsid structures and used cryo-electron microscopy to determine the three-dimensional structure of these particles. The φBB1 procapsids consist of 415 copies of the major capsid protein and an equal combined number of three homologous capsid decoration proteins that form trimeric knobs on the outside of the particle. One of the end vertices of the particle is occupied by a portal assembled from twelve copies of the portal protein. The φBB1 scaffolding protein is entirely α-helical and has an elongated shape with a small globular domain in the middle. Within the tubular section of the procapsid, the internal scaffold is built of stacked rings, each composed of 32 scaffolding protein molecules, which run in opposite directions from both caps with a heterogeneous part in the middle. Inside the portal-containing cap, the scaffold is organized asymmetrically with ten scaffolding protein molecules bound to the portal. The φBB1 procapsid structure provides better insight into the vast structural diversity of bacteriophages and presents clues of how elongated bacteriophage particles might be assembled.
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Affiliation(s)
- Jānis Rūmnieks
- Latvian Biomedical Research and Study Center, Rātsupītes 1, 1067 Riga, Latvia.
| | - Tibor Füzik
- Structural Virology, Central European Institute of Technology, Masaryk University, Kamenice 753/5, 62500 Brno, Czech Republic
| | - Kaspars Tārs
- Latvian Biomedical Research and Study Center, Rātsupītes 1, 1067 Riga, Latvia; Faculty of Biology, University of Latvia, Jelgavas 1, 1004 Riga, Latvia
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2
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Stevenson B, Brissette CA. Erp and Rev Adhesins of the Lyme Disease Spirochete's Ubiquitous cp32 Prophages Assist the Bacterium during Vertebrate Infection. Infect Immun 2023; 91:e0025022. [PMID: 36853019 PMCID: PMC10016077 DOI: 10.1128/iai.00250-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Almost all spirochetes in the genus Borrelia (sensu lato) naturally contain multiple variants of closely related prophages. In the Lyme disease borreliae, these prophages are maintained as circular episomes that are called circular plasmid 32 kb (cp32s). The cp32s of Lyme agents are particularly unique in that they encode two distinct families of lipoproteins, namely, Erp and Rev, that are expressed on the bacterial outer surface during infection of vertebrate hosts. All identified functions of those outer surface proteins involve interactions between the spirochetes and host molecules, as follows: Erp proteins bind plasmin(ogen), laminin, glycosaminoglycans, and/or components of complement and Rev proteins bind fibronectin. Thus, cp32 prophages provide their bacterial hosts with surface proteins that can enhance infection processes, thereby facilitating their own survival. Horizontal transfer via bacteriophage particles increases the spread of beneficial alleles and creates diversity among Erp and Rev proteins.
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Affiliation(s)
- Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky, USA
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
| | - Catherine A. Brissette
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, USA
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3
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Casjens SR, Mongodin EF, Qiu WG, Luft BJ, Schutzer SE, Gilcrease EB, Huang WM, Vujadinovic M, Aron JK, Vargas LC, Freeman S, Radune D, Weidman JF, Dimitrov GI, Khouri HM, Sosa JE, Halpin RA, Dunn JJ, Fraser CM. Genome stability of Lyme disease spirochetes: comparative genomics of Borrelia burgdorferi plasmids. PLoS One 2012; 7:e33280. [PMID: 22432010 PMCID: PMC3303823 DOI: 10.1371/journal.pone.0033280] [Citation(s) in RCA: 125] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 02/06/2012] [Indexed: 11/21/2022] Open
Abstract
Lyme disease is the most common tick-borne human illness in North America. In order to understand the molecular pathogenesis, natural diversity, population structure and epizootic spread of the North American Lyme agent, Borrelia burgdorferi sensu stricto, a much better understanding of the natural diversity of its genome will be required. Towards this end we present a comparative analysis of the nucleotide sequences of the numerous plasmids of B. burgdorferi isolates B31, N40, JD1 and 297. These strains were chosen because they include the three most commonly studied laboratory strains, and because they represent different major genetic lineages and so are informative regarding the genetic diversity and evolution of this organism. A unique feature of Borrelia genomes is that they carry a large number of linear and circular plasmids, and this work shows that strains N40, JD1, 297 and B31 carry related but non-identical sets of 16, 20, 19 and 21 plasmids, respectively, that comprise 33–40% of their genomes. We deduce that there are at least 28 plasmid compatibility types among the four strains. The B. burgdorferi ∼900 Kbp linear chromosomes are evolutionarily exceptionally stable, except for a short ≤20 Kbp plasmid-like section at the right end. A few of the plasmids, including the linear lp54 and circular cp26, are also very stable. We show here that the other plasmids, especially the linear ones, are considerably more variable. Nearly all of the linear plasmids have undergone one or more substantial inter-plasmid rearrangements since their last common ancestor. In spite of these rearrangements and differences in plasmid contents, the overall gene complement of the different isolates has remained relatively constant.
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Affiliation(s)
- Sherwood R Casjens
- Department of Pathology, University of Utah School of Medicine, Salt Lake City, Utah, United States of America.
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Rogers EA, Terekhova D, Zhang HM, Hovis KM, Schwartz I, Marconi RT. Rrp1, a cyclic-di-GMP-producing response regulator, is an important regulator of Borrelia burgdorferi core cellular functions. Mol Microbiol 2009; 71:1551-73. [PMID: 19210621 DOI: 10.1111/j.1365-2958.2009.06621.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two-component systems (TCS) are universal among bacteria and play critical roles in gene regulation. Our understanding of the contributions of TCS in the biology of the Borrelia is just now beginning to develop. Borrelia burgdorferi, a causative agent of Lyme disease, harbours a TCS comprised of open reading frames (ORFs) BB0419 and BB0420. BB0419 encodes a response regulator designated Rrp1, and BB0420 encodes a hybrid histidine kinase-response regulator designated Hpk1. Rrp1, which contains a conserved GGDEF domain, undergoes phosphorylation and produces the secondary messenger, cyclic diguanylate (c-di-GMP), a critical signaling molecule in numerous organisms. However, the regulatory role of the Rrp1-Hpk1 TCS and c-di-GMP signaling in Borrelia biology are unexplored. In this study, the distribution, conservation, expression and potential global regulatory capability of Rrp1 were assessed. rrp1 was found to be universal and highly conserved among isolates, co-transcribed with hpk1, constitutively expressed during in vitro cultivation, and significantly upregulated upon tick feeding. Allelic exchange replacement and microarray analyses revealed that the Rrp1 regulon consists of a large number of genes encoded by the core Borrelia genome (linear chromosome, linear plasmid 54 and circular plasmid 26) that encode for proteins involved in central metabolic processes and virulence mechanisms including immune evasion.
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Affiliation(s)
- Elizabeth A Rogers
- Department of Microbiology and Immunology, Medical College of Virginia Commonwealth University, Richmond, VA, USA
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5
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Abstract
Spirochetes of the genus Borrelia have a highly unusual genome structure composed of over 20 replicons. Most of these replicons are linear and terminated by covalently closed hairpin ends or telomeres. Moreover, the linear replicons are affected by extensive DNA rearrangements, including telomere exchanges, DNA duplications, and harbour a large number of pseudogenes. The mechanism for the unusual genome plasticity in the linear replicons has remained elusive. The enzymatic machinery (the telomere resolvase ResT) responsible for generating the hairpin ends from replicative intermediates has recently been shown to also perform a reverse reaction that fuses telomeres on unrelated replicons. Infrequent stabilization of such fusion events over evolutionary time provides the first proposed biochemical mechanism for the DNA rearrangements that are so prominent in the linear replicons of B. burgdorferi.
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Affiliation(s)
- George Chaconas
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary, Alberta T2N 4N1, Canada.
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Schwan TG, Raffel SJ, Schrumpf ME, Policastro PF, Rawlings JA, Lane RS, Breitschwerdt EB, Porcella SF. Phylogenetic analysis of the spirochetes Borrelia parkeri and Borrelia turicatae and the potential for tick-borne relapsing fever in Florida. J Clin Microbiol 2005; 43:3851-9. [PMID: 16081922 PMCID: PMC1233929 DOI: 10.1128/jcm.43.8.3851-3859.2005] [Citation(s) in RCA: 91] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2005] [Revised: 05/06/2005] [Accepted: 05/13/2005] [Indexed: 11/20/2022] Open
Abstract
Isolates of Borrelia turicatae, Borrelia parkeri, and the Florida canine borrelia (FCB) were examined to further phylogenetically characterize the identities of these spirochetes in the United States. DNA sequences of four chromosomal loci (the 16S rRNA gene, flaB, gyrB, and glpQ) were determined for eight isolates of B. turicatae and six isolates of B. parkeri, which grouped the spirochetes into two distinct but closely related taxa (>98% sequence identity) separate from Borrelia hermsii. The FCB was clearly separated with the group identified as B. turicatae, confirming this bacterium as a relapsing fever spirochete. Therefore, the potential for tick-borne relapsing fever in humans and other animals exists in Florida and future efforts are needed to determine the enzootic hosts and distribution of this spirochete in the southeastern United States. Analysis of plasmids demonstrated both linear and circular forms in B. turicatae but only linear plasmids in B. parkeri, which should be of interest to investigators concerned with plasmid diversity and evolution within this group of spirochetes.
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Affiliation(s)
- Tom G Schwan
- Laboratory of Human Bacterial Pathogenesis, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 903 South 4th St., Hamilton, MT 59840, USA.
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7
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Zhang H, Raji A, Theisen M, Hansen PR, Marconi RT. bdrF2 of Lyme disease spirochetes is coexpressed with a series of cytoplasmic proteins and is produced specifically during early infection. J Bacteriol 2005; 187:175-84. [PMID: 15601701 PMCID: PMC538826 DOI: 10.1128/jb.187.1.175-184.2005] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bdr proteins are polymorphic inner membrane proteins produced by most Borrelia species. In Borrelia burgdorferi B31MI, the18 bdr genes form three subfamilies, bdrD, bdrE, and bdrF. The production of at least one of the Bdr paralogs, BdrF2, is up-regulated in host-adapted spirochetes, suggesting a role for the protein in the mammalian environment. Here, we demonstrate using reverse transcriptase (RT) PCR that BBG29, BBG30, BBG31, and BBG32, which reside upstream of bdrF2, are cotranscribed with bdrF2 as a five-gene operon. While the functions of most of these proteins are unknown, BBG32 encodes a putative DNA helicase. Real-time RT-PCR analyses demonstrated higher levels of bdrF2 transcript relative to other genes of the operon, suggesting that bdrF2 may also be transcribed independently from an internal promoter. Internal promoters were detected using the 5' rapid amplification of cDNA ends system. The putative promoter associated with bdrF2 was found to be highly similar in sequence to the multiple promoters associated with the ospC gene. Real-time RT-PCR analyses, performed to assess the expression of these genes in infected mice, revealed that genes of the bdrF2 locus are expressed only during early infection, suggesting a role in the establishment of infection. To further characterize the proteins encoded by the bdrF2 locus, which have unknown functions, the cellular localizations of these proteins were determined by Triton X-114 extraction and phase partitioning. BBG29 and BBG31 were found to be cytoplasmic. To determine if these proteins elicit an antibody (Ab) response during infection, immunoblot analyses were performed. Abs to these proteins were not detected. Based on the analyses presented here, we offer the hypothesis that BdrF2 and other proteins encoded by the operon form an inner-membrane-associated protein complex that may interact with DNA and which carries out its functional role during transmission or the early stages of infection.
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Affiliation(s)
- Hongming Zhang
- Department of Microbiology and Immunology, Center for the Study of Biological Complexity, Medical College of Virginia at Virginia Commonwealth University, Richmond, Virginia 23298-0678, USA
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8
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Singh SK, Girschick HJ. Molecualar survival strategies of the Lyme disease spirochete Borrelia burgdorferi. THE LANCET. INFECTIOUS DISEASES 2004; 4:575-83. [PMID: 15336225 DOI: 10.1016/s1473-3099(04)01132-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Lyme disease is a tick-transmitted disease caused by the spirochete Borrelia burgdorferi. The bacterium adopts different strategies for its survival inside the immunocompetent host from the time of infection until dissemination in different parts of body tissues. The success of this spirochete depends on its ability to colonise the host tissues and counteract the host's defence mechanisms. During this process borrelia seems to maintain its vitality to ensure long-term survival in the host. Borrelia's proteins are encoded by plasmid and chromosomal genes. These genes are differentially regulated and expressed by different environmental factors in ticks as well as in the mammalian host during infection. In addition, antigenic diversity enables the spirochete to escape host defence mechanisms and maintain infection. In this review we focus on the differential expression of proteins and genes, and further molecular mechanisms used by borrelia to maintain its survival in the host. In light of these pathogenetic mechanisms, further studies on spirochete host interaction are needed to understand the complex interplay that finally lead to host autoimmunity.
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Affiliation(s)
- Sunit Kumar Singh
- Department of Paediatric Rheumatology, Children's Hospital, University of Würzburg, Germany
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Pinne M, Östberg Y, Comstedt P, Bergström S. Molecular analysis of the channel-forming protein P13 and its paralogue family 48 from different Lyme disease Borrelia species. Microbiology (Reading) 2004; 150:549-559. [PMID: 14993304 DOI: 10.1099/mic.0.26728-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The aetiological agent of Lyme disease, Borrelia burgdorferi cycles between its tick vector and mammalian hosts, implying that it can sense different environments and consequently change the expression of genes encoding several surface-associated proteins. The genome of the type strain B. burgdorferi B31 has revealed 175 different gene families. The p13 gene, situated on the chromosome, encodes a channel-forming protein that belongs to the gene family 48 consisting of eight additional paralogous genes. The heterogeneity of the P13 protein from different Lyme disease Borrelia strains was investigated. The predicted surface-exposed domains are the most heterogeneous regions and contain probable epitopes of P13. The membrane-spanning architecture of P13 was determined and a model for the location of this protein in the outer membrane is presented. The transcription of the paralogues of gene family 48 during in vitro culturing and in a mouse infection model was also analysed. The bba01 gene is the only p13 paralogue present in all three Lyme-disease-causing genospecies; it is stable during cultivation in vitro and the BBA01 protein was expressed in all Borrelia strains investigated. Conversely, paralogues bbi31, bbq06 and bbh41 were only detected in B. burgdorferi and the corresponding plasmids harbouring bbi31 and bbh41 were lost during in vitro passage. Finally, p13 and bbi31 are the only members of gene family 48 that are transcribed in mice, suggesting their importance during mammalian infection.
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Affiliation(s)
- Marija Pinne
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Yngve Östberg
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Pär Comstedt
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | - Sven Bergström
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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10
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Roberts DM, Caimano M, McDowell J, Theisen M, Holm A, Orff E, Nelson D, Wikel S, Radolf J, Marconi RT. Environmental regulation and differential production of members of the Bdr protein family of Borrelia burgdorferi. Infect Immun 2002; 70:7033-41. [PMID: 12438383 PMCID: PMC132981 DOI: 10.1128/iai.70.12.7033-7041.2002] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia burgdorferi B31MI carries 18 plasmid-carried genes that form the bdr gene family. The bdr genes of B. burgdorferi encode proteins that form three distinct subfamilies, the BdrD, BdrE, and BdrF subfamilies. bdr orthologs have been demonstrated to be carried by all Borrelia species analyzed, and their widespread distribution suggests that they play an important genus-wide functional role. The biological rationale for maintaining 18 bdr alleles has not been defined. It is our hypothesis that specific paralogs function in different environments and are differentially expressed in response to environmental conditions. As a first step in testing this hypothesis, the production patterns of the Bdr proteins in spirochetes grown under a variety of conditions were assessed through immunoblot analyses. The influence of temperature, serum deprivation, tick feeding, and the mammalian environment on Bdr production was evaluated. These analyses revealed that the synthesis of some Bdr paralogs is environmentally regulated. The production of BdrF(2,) BdrF(1), BdrE(4), and BdrE(5) were upregulated in host-adapted bacteria, while the production levels of other Bdr paralogs were influenced by temperature and serum starvation. These observations suggest that different Bdr paralogs function in different biological environments and provide insight into the biological basis for maintaining multiple members of this gene family.
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Affiliation(s)
- David M Roberts
- Department of Microbiology and Immunology, Medical College of Virginia at Virginia Commonwealth University, Richmond 23298-0678, USA
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11
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Dvornyk V, Vinogradova O, Nevo E. Long-term microclimatic stress causes rapid adaptive radiation of kaiABC clock gene family in a cyanobacterium, Nostoc linckia, from "Evolution Canyons" I and II, Israel. Proc Natl Acad Sci U S A 2002; 99:2082-7. [PMID: 11842226 PMCID: PMC123721 DOI: 10.1073/pnas.261699498] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cyanobacteria are the only prokaryotes known thus far possessing regulation of physiological functions with approximate daily periodicity, or circadian rhythms, that are controlled by a cluster of three genes, kaiA, kaiB, and kaiC. Here we demonstrate considerably higher genetic polymorphism and extremely rapid evolution of the kaiABC gene family in a filamentous cyanobacterium, Nostoc linckia, permanently exposed to the acute natural environmental stress in the two microsite evolutionary models known as "Evolution Canyons," I (Mount Carmel) and II (Upper Galilee) in Israel. The family consists of five distinct subfamilies (kaiI-kaiV) comprising at least 20 functional genes and pseudogenes. The obtained data suggest that the duplications of kai genes have adaptive significance, and some of them are evolutionarily quite recent (approximately 80,000 years ago). The observed patterns of within- and between-subfamily polymorphisms indicate that positive diversifying, balancing, and purifying selections are the principal driving forces of the kai gene family's evolution.
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Affiliation(s)
- Volodymyr Dvornyk
- Institute of Evolution, University of Haifa, Mount Carmel, 31905 Haifa, Israel.
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12
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McDowell JV, Sung SY, Labandeira-Rey M, Skare JT, Marconi RT. Analysis of mechanisms associated with loss of infectivity of clonal populations of Borrelia burgdorferi B31MI. Infect Immun 2001; 69:3670-7. [PMID: 11349029 PMCID: PMC98365 DOI: 10.1128/iai.69.6.3670-3677.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Numerous studies have provided suggestive evidence that the loss of plasmids correlates with the loss of infectivity of the Lyme disease spirochetes. In this study we have further investigated this correlation. Clonal populations were obtained from the skin of a mouse infected for 3 months with a clonal population of Borrelia burgdorferi B31MI. The complete plasmid compositions of these populations were determined using a combination of PCR and Southern hybridization. The infectivities of clones differing in plasmid composition were tested using the C3H-HeJ murine model for Lyme disease. While several clones were found to be noninfectious, a correlation between the loss of a specific plasmid and loss of infectivity in the clones analyzed in this report was not observed. While it is clear from recent studies that the loss of some specific plasmids results in attenuated virulence, this study demonstrates that additional mechanisms also contribute to the loss of infectivity.
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Affiliation(s)
- J V McDowell
- Department of Microbiology and Immunology, School of Medicine, Medical College of Virginia at Virginia Commonwealth University, Richmond 23298-0678, USA
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13
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Roberts DM, Theisen M, Marconi RT. Analysis of the cellular localization of Bdr paralogs in Borrelia burgdorferi, a causative agent of lyme disease: evidence for functional diversity. J Bacteriol 2000; 182:4222-6. [PMID: 10894730 PMCID: PMC101917 DOI: 10.1128/jb.182.15.4222-4226.2000] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bdr (Borrelia direct repeat) gene family of the genus Borrelia encodes a polymorphic group of proteins that carry a central repeat motif region containing putative phosphorylation sites and a hydrophobic carboxyl-terminal domain. It has been postulated that the Bdr proteins may anchor to the inner membrane via the C-terminal domain. In this study, we used cellular fractionation methodologies, salt and detergent treatments, and immunoblot analyses to assess the association of the Bdr proteins with the cellular infrastructure in both Borrelia burgdorferi (a Lyme disease spirochete) and B. turicatae (a relapsing fever spirochete). Triton X-114 extraction and partitioning experiments demonstrated that most Bdr paralogs are associated with the inner membrane-peptidoglycan complex. Analyses of cells treated with the highly chaotropic bile salt detergent deoxycholic acid demonstrated that some Bdr paralogs may also interact with the peptidoglycan, as evidenced by their tight association with the insoluble cellular matrix. In addition, immunoprecipitation (IP) experiments revealed an enhanced IP of all Bdr paralogs when the cell lysates were boiled prior to addition of the precipitating antibody. Furthermore, some Bdr paralogs were accessible to antibody in the IP experiments only in the boiled cell lysates. These observations suggest that different Bdr paralogs may carry out different structural-functional roles. Demonstration of the inner membrane localization of the Bdr proteins and of the differences in nature of the interaction of individual Bdr paralogs with the cell infrastructure is an important step toward defining the functional role of this unique protein family in the genus Borrelia.
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Affiliation(s)
- D M Roberts
- Department of Microbiology and Immunology, School of Medicine, Medical College of Virginia at Virginia Commonwealth University, Richmond, Virginia 23298-0678, USA
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14
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Stevenson B, Porcella SF, Oie KL, Fitzpatrick CA, Raffel SJ, Lubke L, Schrumpf ME, Schwan TG. The relapsing fever spirochete Borrelia hermsii contains multiple, antigen-encoding circular plasmids that are homologous to the cp32 plasmids of Lyme disease spirochetes. Infect Immun 2000; 68:3900-8. [PMID: 10858201 PMCID: PMC101665 DOI: 10.1128/iai.68.7.3900-3908.2000] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Borrelia hermsii, an agent of tick-borne relapsing fever, was found to contain multiple circular plasmids approximately 30 kb in size. Sequencing of a DNA library constructed from circular plasmid fragments enabled assembly of a composite DNA sequence that is homologous to the cp32 plasmid family of the Lyme disease spirochete, B. burgdorferi. Analysis of another relapsing fever bacterium, B. parkeri, indicated that it contains linear homologs of the B. hermsii and B. burgdorferi cp32 plasmids. The B. hermsii cp32 plasmids encode homologs of the B. burgdorferi Mlp and Bdr antigenic proteins and BlyA/BlyB putative hemolysins, but homologs of B. burgdorferi erp genes were absent. Immunoblot analyses demonstrated that relapsing fever patients produced antibodies to Mlp proteins, indicating that those proteins are synthesized by the spirochetes during human infection. Conservation of cp32-encoded genes in different Borrelia species suggests that their protein products serve functions essential to both relapsing fever and Lyme disease spirochetes. Relapsing fever borreliae replicate to high levels in the blood of infected animals, permitting direct detection and possible functional studies of Mlp, Bdr, BlyA/BlyB, and other cp32-encoded proteins in vivo.
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Affiliation(s)
- B Stevenson
- Department of Microbiology and Immunology, University of Kentucky College of Medicine, Lexington, Kentucky 40536-0298, USA.
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15
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Carlyon JA, Roberts DM, Theisen M, Sadler C, Marconi RT. Molecular and immunological analyses of the Borrelia turicatae Bdr protein family. Infect Immun 2000; 68:2369-73. [PMID: 10722647 PMCID: PMC97431 DOI: 10.1128/iai.68.4.2369-2373.2000] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Here, we describe the molecular and immunological characterization of the bdr gene family of Borrelia turicatae, a relapsing-fever spirochete. Nine bdr alleles belonging to two different subfamilies were sequenced and localized to linear plasmids. Anti-Bdr antiserum was generated and used to analyze Bdr expression in pre- and postinfection isogenic populations. The analyses presented here provide a detailed characterization of the Bdr proteins in a relapsing-fever spirochete species, enhancing our understanding of these proteins at the genus-wide level.
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Affiliation(s)
- J A Carlyon
- Department of Microbiology, Medical College of Virginia at Virginia Commonwealth University, Richmond, Virginia 23298, USA
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