Open AccessMolecular analysis of VCA1008: a putative phosphoporin of Vibrio cholerae
Author(s) -
Goulart Carolina L.,
Lery Letícia M.S.,
Diniz Michelle M.P.,
VianezJunior João L.,
NevesFerreira Ana Gisele C.,
Perales Jonas,
Bisch Paulo M,
Von Krüger Wanda M.A.
Publication year - 2009
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2009.01727.x
Subject(s) - vibrio cholerae , porin , biology , bacterial outer membrane , escherichia coli , biochemistry , bacteria , gene , genetics
The PhoB/PhoR‐dependent response to inorganic phosphate (Pi)‐starvation in Vibrio cholerae O1 includes the expression of vc0719 for the response regulator PhoB, vca0033 for an alkaline phosphatase and vca1008 for an outer membrane protein (OMP). Sequences with high identity to these genes have been found in the genome of clinical and environmental strains, suggesting that the Pi‐starvation response in V. cholerae is well conserved. VCA1008, an uncharacterized OMP involved in V. cholerae pathogenicity, presents sequence similarity to porins of Gram‐negative bacteria such as phosphoporin PhoE from Escherichia coli . A three‐dimensional model shows that VCA1008 is a 16‐stranded pore‐forming β‐barrel protein that shares three of the four conserved lysine residues responsible for PhoE anionic specificity with PhoE. VCA1008 β‐barrel apparently forms trimers that collapse into monomers by heating. Properties such as heat modifiability and resistance to denaturation by sodium dodecyl sulfate at lower temperatures permitted us to suggest that VCA1008 is a classical porin, more precisely, a phosphoporin due to its Pi starvation‐induced PhoB‐dependent expression, demonstrated by electrophoretic mobility shift assay and promoter fusion‐ lacZ assays.