Crystal Structures of the Outer Membrane Domain of Intimin and Invasin from Enterohemorrhagic E. coli and Enteropathogenic Y. pseudotuberculosis

Abstract

SUMMARY Intimins and invasins are virulence factors produced by pathogenic Gram-negative bacteria. They contain C-terminal extracellular passenger domains that are involved in adhesion to host cells and N-terminal β-domains that are embedded in the outer membrane. Here, we identify the domain boundaries of an E. coli intimin β-domain and use this information to solve its structure and the β-domain structure of a Y. pseudotuberculosis invasin. Both β-domain structures crystallized as monomers and reveal that the previous range of residues assigned to the β-domain also includes a protease resistant domain that is part of the passenger. Additionally, we identify 146 non-redundant representative members of the intimin/invasin family based on the boundaries of the highly conserved intimin and invasin β-domains. We then use this set of sequences along with our structural data to find and map the evolutionarily constrained residues within the β-domain.

The Zinc Regulated Antivirulence Pathway of Salmonella Is a Multiprotein Immunoglobulin Adhesion System

“…ZirT Domain Delineation-ZirT residues 88 -368 are homologous to the ␤-barrel region of Invasin, or ␤ domain (13,19), and ZirT localizes to the outer membrane where it facilitates the secretion of ZirS (13) and ZirU (Fig. 3B).…”

“…ZirS (zinc regulated secreted) is a 31-kDa protein of unknown function that is secreted by ZirT (zinc regulated transporter), a 72-kDa outer membrane protein (19) with sequence homology to Invasin/Intimin proteins involved in bacterial-host adhesion (13). ZirS and ZirT are predicted to constitute a secretion system with aspects reminiscent of type V two-partner secretion systems (20).…”

Structural comparison of the transport units of type V secretion systems

“…Therefore, this protein was assigned to the new subgroup Vd, termed fused TPS systems (Leo et al, 2012). Recently, the crystal structures of two adhesins, intimin of Escherichia coli and invasin of Yersinia spp., were described (Fairman et al, 2012). These structures revealed architectures similar to those of classical autotransporters of subgroup Va but in reverse order.…”

Femtosecond crystallography of membrane proteins in the lipidic cubic phase

“…Such approaches are routine in traditional crystallography; however, they require sufficiently large crystals to accurately measure Friedel pairs for each reflection and avoid radiation damage decay as much as possible. The first successful experimental phasing of LCP-grown MP crystals was reported in 2012 [27,73,74]. LCP-grown GPCR microcrystals were recently used for phasing by SAD after an overnight soaking with a tantalum bromide cluster [65,75].…”