Structure of the OmpA-like domain of RmpM from Neisseria meningitidis
Article first published online: 4 FEB 2004
Volume 51, Issue 4, pages 1027–1037, February 2004
How to Cite
Grizot, S. and Buchanan, S. K. (2004), Structure of the OmpA-like domain of RmpM from Neisseria meningitidis. Molecular Microbiology, 51: 1027–1037. doi: 10.1111/j.1365-2958.2003.03903.x
- Issue published online: 4 FEB 2004
- Article first published online: 4 FEB 2004
- Accepted 15 October, 2003.
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 Å crystal structure of the C-terminal domain of RmpM. The 150-residue domain adopts a βαβαββ 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.