Structural Mimicry by a Bacterial F Box Effector Hijacks the Host Ubiquitin-Proteasome System

Kathy Wong; John D Perpich; Guennadi Kozlov; Miroslaw Cygler; Yousef Abu Kwaik; Kalle Gehring

doi:10.1016/j.str.2016.12.015

Structural Mimicry by a Bacterial F Box Effector Hijacks the Host Ubiquitin-Proteasome System

Structure. 2017 Feb 7;25(2):376-383. doi: 10.1016/j.str.2016.12.015. Epub 2017 Jan 19.

Authors

Kathy Wong¹, John D Perpich², Guennadi Kozlov¹, Miroslaw Cygler³, Yousef Abu Kwaik², Kalle Gehring⁴

Affiliations

¹ Department of Biochemistry and Groupe de recherche axé sur la structure des protéines, McGill University, Montreal, QC H3G 0B1, Canada.
² Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40202, USA.
³ Department of Biochemistry, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada.
⁴ Department of Biochemistry and Groupe de recherche axé sur la structure des protéines, McGill University, Montreal, QC H3G 0B1, Canada. Electronic address: kalle.gehring@mcgill.ca.

Abstract

Ankyrin B (AnkB/LegAU13) is a translocated F box effector essential for the intracellular replication of the pathogen Legionella pneumophila. AnkB co-opts a host ubiquitin ligase to decorate the pathogen-containing vacuole with K⁴⁸-linked polyubiquitinated proteins and degrade host proteins as a source of energy. Here, we report that AnkB commandeers the host ubiquitin-proteasome system through mimicry of two eukaryotic protein domains. Using X-ray crystallography, we determined the 3D structure of AnkB in complex with Skp1, a component of the human SCF ubiquitination ligase. The structure confirms that AnkB contains an N-terminal F box similar to Skp2 and a C-terminal substrate-binding domain similar to eukaryotic ankyrin repeats. We identified crucial amino acids in the substrate-binding domain of AnkB and showed them to be essential for the function of AnkB in L. pneumophila intracellular proliferation. The study reveals how Legionella uses molecular mimicry to manipulate the host ubiquitination pathway and proliferate intracellularly.

Keywords: E3 ubiquitin ligase; F box protein; X-ray crystallography; ankyrin repeats; bacterial effectors; legionnaires' disease; lpg2144.

MeSH terms

Amino Acid Sequence
Ankyrins / chemistry*
Ankyrins / genetics
Ankyrins / metabolism
Binding Sites
Cell Line
Cloning, Molecular
Crystallography, X-Ray
Escherichia coli / genetics
Escherichia coli / metabolism
Gene Expression
Host-Pathogen Interactions*
Humans
Kinetics
Legionella pneumophila / genetics*
Legionella pneumophila / growth & development
Legionella pneumophila / pathogenicity
Macrophages / microbiology
Models, Molecular
Molecular Mimicry
Periplasmic Proteins / chemistry*
Periplasmic Proteins / genetics
Periplasmic Proteins / metabolism
Proteasome Endopeptidase Complex / metabolism
Protein Binding
Protein Conformation, alpha-Helical
Protein Conformation, beta-Strand
Protein Interaction Domains and Motifs
Recombinant Proteins / chemistry
Recombinant Proteins / genetics
Recombinant Proteins / metabolism
S-Phase Kinase-Associated Proteins / chemistry*
S-Phase Kinase-Associated Proteins / genetics
S-Phase Kinase-Associated Proteins / metabolism
Sequence Alignment
Sequence Homology, Amino Acid
Substrate Specificity
Ubiquitin / chemistry
Ubiquitin / genetics
Ubiquitin / metabolism

Substances

Ankyrins
Periplasmic Proteins
Recombinant Proteins
S-Phase Kinase-Associated Proteins
SKP1 protein, human
Ubiquitin
Proteasome Endopeptidase Complex

Abstract

MeSH terms

Substances

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