8UM2 image
Entry Detail
PDB ID:
8UM2
Keywords:
Title:
Carboxy terminus of Oleate Hydratase in phosphate buffer
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2023-10-17
Release Date:
2024-01-31
Method Details:
Experimental Method:
Conformers Calculated:
100
Conformers Submitted:
20
Selection Criteria:
target function
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Myosin-cross-reactive antigen
Chain IDs:A
Chain Length:42
Number of Molecules:1
Biological Source:Staphylococcus aureus
Ligand Molecules
Primary Citation
The carboxy terminus causes interfacial assembly of oleate hydratase on a membrane bilayer.
J.Biol.Chem. 300 105627 105627 (2024)
PMID: 38211817 DOI: 10.1016/j.jbc.2024.105627

Abstact

The soluble flavoprotein oleate hydratase (OhyA) hydrates the 9-cis double bond of unsaturated fatty acids. OhyA substrates are embedded in membrane bilayers; OhyA must remove the fatty acid from the bilayer and enclose it in the active site. Here, we show that the positively charged helix-turn-helix motif in the carboxy terminus (CTD) is responsible for interacting with the negatively charged phosphatidylglycerol (PG) bilayer. Super-resolution microscopy of Staphylococcus aureus cells expressing green fluorescent protein fused to OhyA or the CTD sequence shows subcellular localization along the cellular boundary, indicating OhyA is membrane-associated and the CTD sequence is sufficient for membrane recruitment. Using cryo-electron microscopy, we solved the OhyA dimer structure and conducted 3D variability analysis of the reconstructions to assess CTD flexibility. Our surface plasmon resonance experiments corroborated that OhyA binds the PG bilayer with nanomolar affinity and we found the CTD sequence has intrinsic PG binding properties. We determined that the nuclear magnetic resonance structure of a peptide containing the CTD sequence resembles the OhyA crystal structure. We observed intermolecular NOE from PG liposome protons next to the phosphate group to the CTD peptide. The addition of paramagnetic MnCl2 indicated the CTD peptide binds the PG surface but does not insert into the bilayer. Molecular dynamics simulations, supported by site-directed mutagenesis experiments, identify key residues in the helix-turn-helix that drive membrane association. The data show that the OhyA CTD binds the phosphate layer of the PG surface to obtain bilayer-embedded unsaturated fatty acids.

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Primary Citation of related structures