MOMP from Campylobacter jejuni Is a Trimer of 18-Stranded β-Barrel Monomers with a Ca²⁺ Ion Bound at the Constriction Zone.

ABSTRACT: The Gram-negative organism Campylobacter jejuni is the major cause of food poisoning. Unlike Escherichia coli, which has two major porins, OmpC and OmpF, C. jejuni has one, termed major outer membrane protein (MOMP) through which nutrients and antibiotics transit. We report the 2.1-Å crystal structure of C. jejuni MOMP expressed in E. coli and a lower resolution but otherwise identical structure purified directly from C. jejuni. The 2.1-Å resolution structure of recombinant MOMP showed that although the protein has timeric arrangement similar to OmpC, it is an 18-stranded, not 16-stranded, β-barrel. The structure has identified a Ca²⁺ bound at the constriction zone, which is functionally significant as suggested by molecular dynamics and single-channel experiments. The water-fil

SUBMITTER: Ferrara LGM 

PROVIDER: S-EPMC5090048 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature