A lysozyme with altered substrate specificity facilitates prey cell exit by the periplasmic predator Bdellovibrio bacteriovorus

DOI: 10.1038/s41467-020-18139-8

Authors: Christopher J. Harding (University of Birmingham) , Simona G. Huwiler (University of Nottingham) , Hannah Somers (University of Nottingham) , Carey Lambert (University of Nottingham) , Luke J. Ray (University of Nottingham) , Rob Till (University of Nottingham) , Georgina Taylor (University of Nottingham) , Patrick J. Moynihan (University of Birmingham) , R. Elizabeth Sockett (University of Nottingham) , Andrew L. Lovering (University of Birmingham)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature Communications , VOL 11

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 14692 , 19880

Abstract: Lysozymes are among the best-characterized enzymes, acting upon the cell wall substrate peptidoglycan. Here, examining the invasive bacterial periplasmic predator Bdellovibrio bacteriovorus, we report a diversified lysozyme, DslA, which acts, unusually, upon (GlcNAc-) deacetylated peptidoglycan. B. bacteriovorus are known to deacetylate the peptidoglycan of the prey bacterium, generating an important chemical difference between prey and self walls and implying usage of a putative deacetyl-specific “exit enzyme”. DslA performs this role, and ΔDslA strains exhibit a delay in leaving from prey. The structure of DslA reveals a modified lysozyme superfamily fold, with several adaptations. Biochemical assays confirm DslA specificity for deacetylated cell wall, and usage of two glutamate residues for catalysis. Exogenous DslA, added ex vivo, is able to prematurely liberate B. bacteriovorus from prey, part-way through the predatory lifecycle. We define a mechanism for specificity that invokes steric selection, and use the resultant motif to identify wider DslA homologues.

Diamond Keywords: Enzymes; Bacteria

Subject Areas: Biology and Bio-materials, Chemistry, Medicine


Instruments: I03-Macromolecular Crystallography , I04-1-Macromolecular Crystallography (fixed wavelength) , I04-Macromolecular Crystallography

Added On: 30/09/2020 10:01

Documents:
s41467-020-18139-8.pdf

Discipline Tags:

Pathogens Antibiotic Resistance Infectious Diseases Health & Wellbeing Biochemistry Catalysis Chemistry Structural biology Drug Discovery Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)