PDBsum entry 1otm

Cell adhesion

PDB id: 1otm

Contents

Protein chain

207 a.a. *

Waters ×123

* Residue conservation analysis

PDB id:

1otm

Name:

Cell adhesion

Title:

Calcium-binding mutant of the internalin b lrr domain

Structure:

Internalin b. Chain: a. Fragment: lrr domain. Engineered: yes. Mutation: yes

Source:

Listeria monocytogenes. Organism_taxid: 1639. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Resolution:

1.93Å R-factor: 0.201 R-free: 0.240

Authors:

M.Marino,J.Copp,S.Dramsi,T.Chapman,P.Van Der Geer,P.Cossart,P.Ghosh

Key ref:

M.Marino et al. (2004). Characterization of the calcium-binding sites of Listeria monocytogenes InlB. Biochem Biophys Res Commun, 316, 379-386. PubMed id: 15020228 DOI: 10.1016/j.bbrc.2004.02.064

Date:

21-Mar-03 Release date: 30-Mar-04

Protein chain

P0DQD2  (INLB_LISMO) -  Internalin B from Listeria monocytogenes serovar 1/2a (strain ATCC BAA-679 / EGD-e)

Seq: 630 a.a.

Struc: 207 a.a.*

* PDB and UniProt seqs differ at 6 residue positions (black crosses)

DOI no: 10.1016/j.bbrc.2004.02.064

Biochem Biophys Res Commun 316:379-386 (2004)

PubMed id: 15020228

Characterization of the calcium-binding sites of Listeria monocytogenes InlB.

M.Marino, M.Banerjee, J.Copp, S.Dramsi, T.Chapman, P.van der Geer, P.Cossart, P.Ghosh.

ABSTRACT

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.