The foodborne enteric pathogen Campylobacter jejuni decorates a variety of its cell-surface structures with phosphoethanolamine (pEtN). Modifying lipid A with pEtN promotes cationic antimicrobial peptide resistance, whereas post-translationally modifying the flagellar rod protein FlgG with pEtN promotes flagellar assembly and motility, which are processes that are important for intestinal colonization. EptC, the pEtN transferase required for all known pEtN cell-surface modifications in C. jejuni, is a predicted inner-membrane metalloenzyme with a five-helix N-terminal transmembrane domain followed by a soluble sulfatase-like catalytic domain in the periplasm. The atomic structure of the catalytic domain of EptC (cEptC) was crystallized and solved to a resolution of 2.40 angstrom. cEptC adopts the alpha/beta/alpha fold of the sulfatase protein family and harbors a zinc-binding site. A phosphorylated Thr266 residue was observed that was hypothesized to mimic a covalent pEtN-enzyme intermediate. The requirement for Thr266 as well as the nearby residues Asn308, Ser309, His358 and His440 was ascertained via in vivo activity assays on mutant strains. The results establish a basis for the design of pEtN transferase inhibitors.National Institutes of Health (grants AI064184, AI076322, GM106112Army Research Office (grantW911NF-12-1-0390)College of Natural SciencesOffice of the Executive Vice President and ProvostInstitute for Cellular and Molecular Biology at the University of Texas at AustinUS DOE DE-AC02-06CH11357National Institute of General Medical SciencesHoward Hughes Medical InstituteOffice of Science, Office of Basic Energy Sciences of the US Department of Energy DE-AC02-05CH11231Maria
Person and the Proteomics Facility at the University of Texas at Austin ES007784 (CRED) and
RP110782 (CPRIT)Molecular Bioscience
