7AM0 image
Entry Detail
PDB ID:
7AM0
Keywords:
Title:
GqqA- a novel type of quorum quenching acylases
Biological Source:
PDB Version:
Deposition Date:
2020-10-07
Release Date:
2021-08-04
Method Details:
Experimental Method:
Resolution:
2.50 Å
R-Value Free:
0.27
R-Value Work:
0.23
R-Value Observed:
0.23
Space Group:
P 1 21 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Prephenate dehydratase
Chain IDs:A, B, C, D
Chain Length:281
Number of Molecules:4
Biological Source:Komagataeibacter europaeus
Ligand Molecules
Primary Citation
The Komagataeibacter europaeus GqqA is the prototype of a novel bifunctional N-Acyl-homoserine lactone acylase with prephenate dehydratase activity.
Sci Rep 11 12255 12255 (2021)
PMID: 34112823 DOI: 10.1038/s41598-021-91536-1

Abstact

Previously, we reported the isolation of a quorum quenching protein (QQ), designated GqqA, from Komagataeibacter europaeus CECT 8546 that is highly homologous to prephenate dehydratases (PDT) (Valera et al. in Microb Cell Fact 15, 88. https://doi.org/10.1186/s12934-016-0482-y , 2016). GqqA strongly interfered with N-acyl-homoserine lactone (AHL) quorum sensing signals from Gram-negative bacteria and affected biofilm formation in its native host strain Komagataeibacter europaeus. Here we present and discuss data identifying GqqA as a novel acylase. ESI-MS-MS data showed unambiguously that GqqA hydrolyzes the amide bond of the acyl side-chain of AHL molecules, but not the lactone ring. Consistent with this observation the protein sequence does not carry a conserved Zn2+ binding motif, known to be essential for metal-dependent lactonases, but in fact harboring the typical periplasmatic binding protein domain (PBP domain), acting as catalytic domain. We report structural details for the native structure at 2.5 Å resolution and for a truncated GqqA structure at 1.7 Å. The structures obtained highlight that GqqA acts as a dimer and complementary docking studies indicate that the lactone ring of the substrate binds within a cleft of the PBP domain and interacts with polar residues Y16, S17 and T174. The biochemical and phylogenetic analyses imply that GqqA represents the first member of a novel type of QQ family enzymes.

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