6ta9
Bd0314 DslA wild-type form 1
Structural highlights
Publication Abstract from PubMedLysozymes 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 DeltaDslA 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. A lysozyme with altered substrate specificity facilitates prey cell exit by the periplasmic predator Bdellovibrio bacteriovorus.,Harding CJ, Huwiler SG, Somers H, Lambert C, Ray LJ, Till R, Taylor G, Moynihan PJ, Sockett RE, Lovering AL Nat Commun. 2020 Sep 23;11(1):4817. doi: 10.1038/s41467-020-18139-8. PMID:32968056[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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