4AW4

Engineered variant of Listeria monocytogenes InlB internalin domain with an additional leucine rich repeat inserted

Summary for 4AW4

• Entry DOI: 10.2210/pdb4aw4/pdb
• Related: 1D0B 1H6T 1M9S 1OTM 1OTN 1OTO 2UZX 2UZY 2WQU 2WQV 2WQW 2WQX 2Y5P 2Y5Q
• Descriptor: INTERNALIN B, SULFATE ION, GLYCEROL, ... (4 entities in total)
• Functional Keywords: protein binding, lrr, protein engineering, receptor binding, protein protein interaction, cell invasion, virulence factor, hgf receptor ligand, c-met ligand
• Biological source: LISTERIA MONOCYTOGENES
• Total number of polymer chains: 3
• Total formula weight: 107179.93

Authors

Niemann, H.H.,Heinz, D.W. (deposition date: 2012-05-31, release date: 2012-08-15, Last modification date: 2023-12-20)

Primary citation

Niemann, H.H.,Gherardi, E.,Bleymuller, W.M.,Heinz, D.W.
Engineered Variants of Inlb with an Additional Leucine-Rich Repeat Discriminate between Physiologically Relevant and Packing Contacts in Crystal Structures of the Inlb:Met Complex.
Protein Sci., 21:1528-, 2012

PubMed Abstract: The physiological relevance of contacts in crystal lattices often remains elusive. This was also the case for the complex between the invasion protein internalin B (InlB) from Listeria monocytogenes and its host cell receptor, the human receptor tyrosine kinase (RTK) MET. InlB is a MET agonist and induces bacterial host cell invasion. Activation of RTKs generally involves ligand-induced dimerization of the receptor ectodomain. The two currently available crystal structures of the InlB:MET complex show the same arrangement of InlB and MET in a 1:1 complex, but different dimeric 2:2 assemblies. Only one of these 2:2 assemblies is predicted to be stable by a computational procedure. This assembly is mainly stabilized by a contact between the Cap domain of InlB from one and the Sema domain of MET from another 1:1 complex. Here, we probe the physiological relevance of this interaction. We generated variants of the leucine-rich repeat (LRR) protein InlB by inserting an additional repeat between the first and the second LRR. This should allow formation of the 1:1 complex but disrupt the potential 2:2 complex involving the Cap-Sema contact due to steric distortions. A crystal structure of one of the engineered proteins showed that it folded properly. Binding affinity to MET was comparable to that of wild-type InlB. The InlB variant induced MET phosphorylation and cell scatter like wild-type InlB. These results suggest that the Cap-Sema interaction is not physiologically relevant and support the previously proposed assembly, in which a 2:2 InlB:MET complex is built around a ligand dimer.

PubMed: 22887347
DOI: 10.1002/PRO.2142

Experimental method

X-RAY DIFFRACTION (1.93 Å)