Analysis Biomolecular Interactions of GfcB, GfcC, and GfcD proteins by BLI (CAT#: STEM-MB-0130-CJ)

Introduction

The gfcABCD and homologous operons of other species—Vibrio cholera O139 wbfDCB, Vibrio anguillarum wbfDCB, Aeromonas hydrophila gfcABCD and the E. coli yjbEFGH—have functions linked to capsule or exopolysaccharide production. E. coli gfcA, the shortest gene, has an unusually rich percentage of threonine residues (30%) and may encode a 101-amino acid inner membrane or secreted protein. The gfcB gene was identified in a screen of E. coli O157:H7 gene disruptions that impaired colonization of a bovine host suggesting that GfcB is involved in virulence. GfcB, GfcC, and GfcD all contain predicted signal sequences for export to the periplasm. The signal sequences of GfcB and GfcD also contain lipobox motifs including cysteine residue(s) that would becleaved with signal peptidase II, modified with acyl groups, and localized to the cell outer membrane. GfcD is annotated as a putative lipoprotein in many of the online sequence databases, but an alternative site for signal peptidase 1 cleavage was predicted by SignalP 4.0 indicative of a non-lipidated protein. Further, GfcD is predicted with high likelihood to belong to the cluster OMP.nn.30.1 of outer membrane β-barrels in the HHOMP database.