1OTN: Calcium-binding Mutant Of The Internalin B Lrr Domain

The Listeria monocytogenes protein InlB promotes invasion of mammalian cells through activation of the receptor tyrosine kinase Met. The InlB N-cap, a approximately 40 residue part of the domain that binds Met, was previously observed to bind two calcium ions in a novel and unusually exposed manner. Because subsequent work raised questions about the existence of these calcium-binding sites, we assayed calcium binding in solution to the InlB N-cap. We show that calcium ions are bound with dissociation constants in the low micromolar range at the two identified sites, and that the sites interact with one another. We demonstrate that the calcium ions are not required for structure, and also find that they have no appreciable effect on Met activation or intracellular invasion. Therefore, our results indicate that the sites are fortuitous in InlB, but also suggest that the simple architecture of the sites may be adaptable for protein engineering purposes.
PDB ID: 1OTNDownload
MMDB ID: 26792
PDB Deposition Date: 2003/3/21
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.97  Å
Source Organism:
Similar Structures:
Biological Unit for 1OTN: monomeric; determined by author
Molecular Components in 1OTN
Label Count Molecule
Protein (1 molecule)
Internalin B(Gene symbol: inlB)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB