RESUMO
We previously described a bacteriophage of the Lyme disease agent Borrelia burgdorferi designated phiBB-1. This phage packages the host complement of the 32-kb circular plasmids (cp32s), a group of homologous molecules found throughout the genus Borrelia. To demonstrate the ability of phiBB-1 to package and transduce DNA, a kanamycin resistance cassette was inserted into a cloned fragment of phage DNA, and the resulting construct was transformed into B. burgdorferi CA-11.2A cells. The kan cassette recombined into a resident cp32 and was stably maintained. The cp32 containing the kan cassette was packaged by phiBB-1 released from this B. burgdorferi strain. phiBB-1 has been used to transduce this antibiotic resistance marker into naive CA-11.2A cells, as well as two other strains of B. burgdorferi. This is the first direct evidence of a mechanism for lateral gene transfer in B. burgdorferi.
Assuntos
Bacteriófagos/genética , Bacteriófagos/fisiologia , Grupo Borrelia Burgdorferi/genética , Grupo Borrelia Burgdorferi/virologia , Resistência a Canamicina/genética , Bacteriófagos/ultraestrutura , Clonagem Molecular , Elementos de DNA Transponíveis , DNA Bacteriano/genética , DNA Viral/genética , Teste de Complementação Genética , Plasmídeos , Reação em Cadeia da Polimerase , Mapeamento por Restrição , Transdução Genética , Transformação GenéticaRESUMO
The C-terminal domain of the A subunit of DNA gyrase, which we term Gac, is naturally synthesized in Borrelia burgdorferi as an abundant DNA-binding protein. Full-length GyrA, which includes the C-terminal domain, is also synthesized by the spirochete and functions as a subunit of DNA gyrase. We have disrupted synthesis of Gac as an independent protein and demonstrated that it is not essential for growth in a coumarin-resistant background. We detected no alterations in DNA maintenance, condensation, or topology in B. burgdorferi lacking this small DNA-binding protein.