Database accession: MF7000494
Name: FosB with Fosfomycin (Enterococcus faecium)
PDB ID: 7n7g
Experimental method: X-ray (2.00 Å)
Assembly: Homodimer
Source organism: Enterococcus faecium
Primary publication of the structure:
Wiltsie V, Travis S, Shay MR, Simmons Z, Frantom P, Thompson MK
Structural and functional characterization of fosfomycin resistance conferred by FosB from Enterococcus faecium.
(2022) Protein Sci. 31: 580-590
PMID: 34882867
Abstract:
The Gram-positive pathogen Enterococcus faecium is one of the leading causes of hospital-acquired vancomycin resistant enterococci (VRE) infections. E. faecium has extensive multidrug resistance and accounts for more than two million infections in the United States each year. FosB is a fosfomycin resistance enzyme found in Gram-positive pathogens like E. faecium. Typically, the FosB enzymes are Mn2+ -dependent bacillithiol (BSH) transferases that inactivate fosfomycin through nucleophilic addition of the thiol to the antibiotic. However, our kinetic analysis of FosBEf shows that the enzyme does not utilize BSH as a thiol substrate, unlike the other well characterized FosB enzymes. Here we report that FosBEf is a Mn2+ -dependent L-cys transferase. In addition, we have determined the three-dimensional X-ray crystal structure of FosBEf in complex with fosfomycin at a resolution of 2.0 Å. A sequence similarity network (SSN) was generated for the FosB family to investigate the unexpected substrate selectivity. Three non-conserved residues were identified in the SSN that may contribute to the substrate selectivity differences in the family of enzymes. Our structural and functional characterization of FosBEf establishes the enzyme as a potential target and may prove useful for future structure-based development of FosB inhibitors to increase the efficacy of fosfomycin.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
metal ion binding metal ion binding
transferase activity, transferring alkyl or aryl (other than methyl) groups transferase activity, transferring alkyl or aryl (other than methyl) groups
Biological process:
response to antibiotic response to antibiotic
Cellular component:
cytoplasm cytoplasm
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Metallothiol transferase FosB
Source organism: Enterococcus faecium
Length: 139 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMIKGINHITYSVSNIAKSIEFYRDILGADILVESETLAYFNLGGIWLALNEEKNIPRSEIKYSYTHIAFTISDNDFEDWYNWLKENEVNILEGRDRDIRDKKSIYFTDLDGHKLELHTGSLEDRLSYYKEAKPHMNFYI
UniProtKB AC: F1C939 (positions: 1-138)
Coverage: 99%
Name: Metallothiol transferase FosB
Source organism: Enterococcus faecium
Length: 139 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMIKGINHITYSVSNIAKSIEFYRDILGADILVESETLAYFNLGGIWLALNEEKNIPRSEIKYSYTHIAFTISDNDFEDWYNWLKENEVNILEGRDRDIRDKKSIYFTDLDGHKLELHTGSLEDRLSYYKEAKPHMNFYI
UniProtKB AC: F1C939 (positions: 1-139)
Coverage: 100%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Glyoxalase/Bleomycin resistance protein/Dioxygenase superfamily
Evidence level: Indirect evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
The VOC superfamily of metalloenzymes is characterized by a three-dimensional domain-swapped arrangement of tandem βαβββ-motifs (PMID:24447055). The original gene duplication event led to the βαβββ tandem structure, which appears to require dimerization for stability. Two different forms of domain-swapped dimers may coexist in solution (PMID:12121648) in which both subunits of the homodimer participate in coordination of each metal ion and formation of the U-shaped active sites in the enzyme (PMID:24004181). The complex is predominantly dimeric in solution (gel filtration) (PMID:12121648).
Chain A:
N/A
Chain B:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
Download this entry's XML file (.xml)
Download this entry's JSON file (.json)
