Part:BBa_K3128031

Outer Membrane Protein X (OmpX) WT gene

The integral outer membrane protein X (OmpX) from Escherichia coli belongs to a family of highly conserved bacterial proteins. Its role is to promote bacterial adhesion and entry into mammalian cells. These proteins have a role in the resistance against attack by the human complement system.(1)

Structure

OmpX consists of an eight-stranded antiparallel all-next-neighbor beta barrel. The structure shows two girdles of aromatic amino acid residues and a ribbon of nonpolar residues that attach to the membrane interior. The core of the barrel consists of an extended hydrogen-bonding network of highly conserved residues. OmpX thus resembles an inverse micelle. (1)

Figure 1: Crystal structure and amino acid sequence of OmpX. (A) Structure of OmpX. The eight β-strands are in gray, and the four extracellular loops (EL) and three periplasmic loops (PL) are in yellow. (B) Amino acid sequence and structural organization of OmpX. Residues in β-strands are in squares, and residues in loops are in circles. Transmembrane residues on the barrel surface are shown in gray. The first strand is shown twice to illustrate the cylindrical connection. Dashed lines indicate hydrogen bonds. Adapted from reference (1).

References

⁽¹⁾ Vogt, J., Schulz G. The structure of the outer membrane protein OmpX from Escherichia coli reveals possible mechanisms of virulence. 1999