Multiple circular and linear plasmids of Lyme disease and relapsing fever
Multiple circular and linear plasmids of Lyme disease and relapsing fever spirochetes carry genes for members of the Bdr (direct repeat) protein family. and proteins which are expressed in the course of Lyme disease and in vitro. Spirochetes of the genus are host-associated microorganisms that cycle between vertebrate hosts by means of arthropod vectors (10). sensu lato, including (16), (5), (18), and many various other carefully related genospecies perhaps, will be the etiologic agencies of Lyme disease (50). A phylogenetically specific group which includes and (39) are factors behind relapsing fever (10). The genome of types includes a 1-Mb linear chromosome (13, 25) complemented by a lot of linear plasmids (lps) and round plasmids (cps) 10 to 60 kb in proportions (7, 46, 56, 61). cps and lps have already been proven to talk about common sequences (8, 47, 48, 56, 61, 63, 64) and, in the entire case of the plasmid, can can be found in both linear NVP-BEZ235 and round forms (26). As lps as well as the chromosome may actually have exchanged hereditary information (21) plus some from the cps bring genes usually entirely on chromosomes of various other prokaryotes (36), plasmids have already been likened to minichromosomes (6). Both lps and cps are near if not really equimolar using the chromosome (32, 34). Peculiar in this respect is certainly a family group of cps about 32 kb in proportions (cp32s) that are nearly identical in hereditary information. In stress B31, eight of a complete of NVP-BEZ235 nine specific plasmids (numbered cp32-1 to cp32-9) have ITM2A already been determined within a clonal bacterial lifestyle (22, 56). Equivalent cp32s or variations thereof have already been found in various other sensu lato isolates (24, 28, 37, 47, 54). Lately, was proven to contain multiple related cp32s (51). This existence of several virtually identical yet not similar plasmid series entities within one cell qualified prospects to a bunch of paralogous gene households. Three separate cp32-encoded loci have already been analyzed and sequenced to different extents. One of the most in-depth research to date have got dealt with people from the Erp lipoprotein family members, which are linked to OspF and OspE, differentially portrayed and immunogenic in mammals (52, 56). Two open up reading structures (ORFs) originally defined as component of a hereditary locus termed present on seven cp32s of 297, and (37), possess recently been proven to code for proteins with hemolytic activity in B31 (BlyA and BlyB ). Another locus comprising five ORFs (ORF-1, -2, -C, -3, and -E) flanked by inverted repeats was determined partly by Dunn and co-workers (24) and inside our earlier studies on repeated DNA of Lyme disease spirochetes (48, 63, 64). The functions of the ORFs remain unknown. ORF-2 has been postulated to represent a RepC homolog (24), while ORF-C resembled bacterial proteins involved in plasmid partitioning (8, 53, 64). The last ORF in this locus, originally named ORF-E, featured multiple internal 33- and 21-bp-long direct in-frame repeats, suggesting a repeated protein motif domain name. Two complete ORF-E copies were NVP-BEZ235 identified on one of the multiple homologous cp32s and the related lp56 of B31. The predicted polypeptides had 64% overall amino acid identity. Intriguingly, they varied NVP-BEZ235 in the number of direct repeat units and thus in size (24.1 and 20.6 kDa, respectively) (64). We hypothesized that these two ORF products represented members of a protein family. To date, a total of 29 ORF-E homologs have been described under various names in strain B31 (20, 28) and other sensu lato isolates (1, 37, 54, 57) as well as other species (19, 51). To define the common and divergent characteristics of this protein family, we first undertook a comprehensive comparison of all known paralogs (i.e., intraspecies homologs) and orthologs (i.e., interspecies homologs). We then investigated their possible biological.