Structural and functional studies indicate that Shigella VirA is not a protease and does not directly destabilize microtubules.
Germane, K.L., Ohi, R., Goldberg, M.B., Spiller, B.W.(2008) Biochemistry 47: 10241-10243
- PubMed: 18763811 
- DOI: https://doi.org/10.1021/bi801533k
- Primary Citation of Related Structures:  
3EB8 - PubMed Abstract: 
VirA, an essential virulence factor in Shigella disease pathogenesis, is involved in the uptake, motility, and cell-to-cell spread of Shigella organisms within the human host. These functions have been attributed to a VirA protease activity and a mechanism of microtubule destruction via tubulin degradation [Yoshida, S., et al. (2006) Science 314, 985-989]. We report functional and crystallographic data indicating a novel VirA structure that lacks these activities but highlights the homology to the EspG virulence factor of pathogenic Escherichia coli.
Organizational Affiliation: 
Department of Pharmacology, Vanderbilt University Medical Center, 461 Preston Research Building, 2220 Pierce Avenue, Nashville, Tennessee 37232, USA.