Osa protein encoded by plasmid pSa is located at the inner membrane but does not inhibit membrane association of VirB and VirD virulence proteins in Agrobacterium tumefaciens
Journal
FEMS Microbiology Letters
Journal Volume
135
Journal Issue
1
Pages
85-92
Date Issued
1996
Author(s)
Kado C.I.
Abstract
The osu gene of IncW plasmid pSa encodes a 21-kDa protein that completely abolishes the oncogenic activity encoded by virulence genes in Agrohacterium tumefaciens.osa is the last gene of a four-gene operon in pSa, the expression of which appears to be highly regulated since the Osa protein is absent when either pSa or the osu operon is present in the Apdcrctrriurn cell.When the osa gene alone or together with upstream genes within the operon are expressed under the control of a constitutive promoter, Osa protein is produced, enabling us to determine its subcellular location.Immunoblot analyses located Osa protein at the inner membrane of both A. tumefuciens and Ercherichiu co/i.Because Osa inhibits oncogenicity of A. tumqfucien.s, and because alterations of the products of the c,irB and l,irD genes affect oncagenicity.studies were conducted to determine if there are changes in their specific association with the membranes in the presence Osa.Immunoblot analyses of VirB2, VirB3, VirB4, VirB9, and VirD4 in the presence and absence of Osa revealed no differences between the two treatments in these Vir protein associations with the membranes.These results indicate that both rirB and GrD gene products are produced in the presence of Osa; that they appear unaffected in their association with the membranes: and that Osa is associated with the inner membrane.where VirB2, VirB4, and VirD4 proteins are also located.
SDGs
Type
journal article