Cellular localization and functional analysis of the protein encoded by the chromosomal virulence gene(acvB) of Agrobacterium tumefaciens.
A chromosomal virulence gene, acvB, of Agrobacterium tumefaciens [J. Bacteriol., 175, 3208-3212 (1993)] was over-expressed in Escherichia coli. A 47-kDa protein was produced and localized in the periplasmic space of E. coli. Amino acid sequence analysis of its N-terminal demonstrated that a signal peptide of 24 amino acids was cleaved from the pre AcvB protein to produce the mature 47-kDa protein. Western-blot analysis using the antiserum against the AcvB protein detected a 47-kDa protein in the periplasmic space only with strain A208 (acvB+). The amount of AcvB protein synthesized was not increased in strain A208 by induction with acetosyringone (100 microM). There was observed no significant difference in induction by acetosyringone of virB::lacZ, virD::lacZ, and virE::lacZ fusion genes regardless of the presence or absence of the acvB gene. The T-strand (lower strand of T-DNA) was detected in strains A208 as well as B119 (acvB-) which were cultured in induction medium containing acetosyringone. AcvB protein bound to single-stranded DNAs with no apparent sequence specificity. The results suggest that AcvB protein binds to the T-strand in periplasm and mediates the transfer of the T-strand from A. tumefaciens to the host plant cell.
Kang
H W
HW
Nagoya University Bioscience Center, Japan.
Wirawan
I G
IG
Kojima
M
M
D000098:Acetophenones / Q000494:pharmacology; D016960:Agrobacterium tumefaciens / Q000235:genetics*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors
D000098:Acetophenones; C090801:AcvB protein, Agrobacterium tumefaciens; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D037521:Virulence Factors; C051667:acetosyringone