Cloning, sequencing, and expression of three Bartonella henselae genes homologous to the Agrobacterium tumefaciens VirB region.
A 17-kDa, immunodominant antigen of Bartonella henselae Houston-1 has previously been cloned, sequenced, and characterized. This clone (H13) contains the 17-kDa antigen gene plus a partial open reading frame, designated ORF1, which is 459 nucleotides long and is directly upstream of the 17-kDa gene. Comparison of the deduced partial amino acid sequence of ORF1 with that of other known genes in GenBank revealed significant identity with several other bacterial virulence genes, including VirB4 of the Agrobacterium tumefaciens virB operon (56/149 amino acids). An overlapping clone, pGB3, was recovered and shown to contain a 3.0-kb region upstream of the 17-kDa gene. Sequence analysis revealed three ORFs upstream of the gene. The deduced amino acid sequence of each ORF was compared with sequences in GenBank, and identity was found with VirB2, VirB3, and VirB4 of A. tumefaciens. In vitro transcription/translation and SDS-PAGE demonstrated that three proteins of 9 kDa, 10 kDa, and 92 kDa, corresponding to the predicted molecular weight of 10.9 kDa, 11.7 kDa, and 89.9 kDa of VirB2, VirB3, and VirB4, respectively, could be expressed from these coding regions. These results indicate that virulence-associated genes and their overall chromosomal arrangement are relatively well conserved between B. henselae and other gram-negative bacteria such as A. tumefaciens.
Schmiederer
M
M
Department of Medical Microbiology and Immunology, University of South Florida, College of Medicine, Tampa 33612, USA.
Anderson
B
B
D016960:Agrobacterium tumefaciens / Q000235:genetics*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics*; D018416:Bartonella henselae / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D005798:Genes, Bacterial; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors
D001426:Bacterial Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D037521:Virulence Factors