Structure of the OmpA-like domain of RmpM from Neisseria meningitidisGrizot, S., Buchanan, S.K.
(2004) Mol Microbiol 51: 1027-1037
- PubMed: 14763978
- DOI: https://doi.org/10.1111/j.1365-2958.2003.03903.x
- Primary Citation of Related Structures:
- PubMed Abstract:
RmpM is a putative peptidoglycan binding protein from Neisseria meningitidis that has been shown to interact with integral outer membrane proteins such as porins and TonB-dependent transporters. Here we report the 1.9 A crystal structure of the C-terminal domain of RmpM. The 150-residue domain adopts a betaalphabetaalphabetabeta fold, as first identified in Bacillus subtilis chorismate mutase. The C-terminal RmpM domain is homologous to the periplasmic, C-terminal domain of Escherichia coli OmpA; these domains are thought to be responsible for non-covalent interactions with peptidoglycan. From the structure of the OmpA-like domain of RmpM, we suggest a putative peptidoglycan binding site and identify residues that may be essential for binding. Both the crystal structure and solution experiments indicate that RmpM may exist as a dimer. This would promote more efficient peptidoglycan binding, by allowing RmpM to interact simultaneously with two glycan chains through its C-terminal, OmpA-like binding domain, while its (structurally uncharacterized) N-terminal domain could stabilize oligomers of porins and TonB-dependent transporters in the outer membrane.
Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health , Department of Health and Human Services, Bethesda, Maryland 20892, USA.