Download MendeleyHexamers of the Type II Secretion ATPase GspE from Vibrio cholerae with Increased ATPase Activity.
Lu, C., Turley, S., Marionni, S.T., Park, Y.J., Lee, K.K., Patrick, M., Shah, R., Sandkvist, M., Bush, M.F., Hol, W.G.(2013) Structure 21: 1707-1717
- PubMed: 23954505
- DOI: https://doi.org/10.1016/j.str.2013.06.027
- Primary Citation of Related Structures:
4KSR, 4KSS - PubMed Abstract:
The type II secretion system (T2SS), a multiprotein machinery spanning two membranes in Gram-negative bacteria, is responsible for the secretion of folded proteins from the periplasm across the outer membrane. The critical multidomain T2SS assembly ATPase GspE(EpsE) had not been structurally characterized as a hexamer. Here, four hexamers of Vibrio cholerae GspE(EpsE) are obtained when fused to Hcp1 as an assistant hexamer, as shown with native mass spectrometry. The enzymatic activity of the GspE(EpsE)-Hcp1 fusions is ∼20 times higher than that of a GspE(EpsE) monomer, indicating that increasing the local concentration of GspE(EpsE) by the fusion strategy was successful. Crystal structures of GspE(EpsE)-Hcp1 fusions with different linker lengths reveal regular and elongated hexamers of GspE(EpsE) with major differences in domain orientation within subunits, and in subunit assembly. SAXS studies on GspE(EpsE)-Hcp1 fusions suggest that even further variability in GspE(EpsE) hexamer architecture is likely.
Organizational Affiliation:
Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.
