PDBsum entry 1r9c

Transferase

PDB id: 1r9c

Contents

Protein chains

125 a.a. *

118 a.a. *

Metals

_MN ×2

Waters ×121

* Residue conservation analysis

PDB id:

1r9c

Name:

Transferase

Title:

Crystal structure of fosfomycin resistance protein fosx from mesorhizobium loti

Structure:

Glutathione transferase. Chain: a, b. Engineered: yes

Source:

Mesorhizobium loti. Organism_taxid: 381. Gene: fosfomycin resistance protein. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

Biol. unit:

Dimer (from PQS)

Resolution:

1.83Å R-factor: 0.205 R-free: 0.243

Authors:

K.L.Fillgrove,S.Pakhomova,M.E.Newcomer,R.N.Armstrong

Key ref:

K.L.Fillgrove et al. (2003). Mechanistic diversity of fosfomycin resistance in pathogenic microorganisms. J Am Chem Soc, 125, 15730-15731. PubMed id: 14677948 DOI: 10.1021/ja039307z

Date:

28-Oct-03 Release date: 10-Feb-04

Protein chain

Q98GG1  (FOSX_RHILO) -  Fosfomycin resistance protein FosX from Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099)

Seq: 139 a.a.

Struc: 125 a.a.

Protein chain

Q98GG1  (FOSX_RHILO) -  Fosfomycin resistance protein FosX from Mesorhizobium japonicum (strain LMG 29417 / CECT 9101 / MAFF 303099)

Seq: 139 a.a.

Struc: 118 a.a.

Enzyme reactions

• Enzyme class: Chains A, B: E.C.2.5.1.1 - dimethylallyltranstransferase.
• Pathway: Terpenoid biosynthesis
• Reaction: isopentenyl diphosphate + dimethylallyl diphosphate = (2E)- geranyl diphosphate + diphosphate

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

reference

DOI no: 10.1021/ja039307z

J Am Chem Soc 125:15730-15731 (2003)

PubMed id: 14677948

Mechanistic diversity of fosfomycin resistance in pathogenic microorganisms.

K.L.Fillgrove, S.Pakhomova, M.E.Newcomer, R.N.Armstrong.

ABSTRACT

Microbial resistance to the antibiotic fosfomycin [(1R,2S)-epoxypropylphosphonic acid, 1] is known to be mediated by thiol transferase enzymes FosA and FosB, which catalyze the addition of glutathione and l-cysteine to C1 of the oxirane, respectively. A probe of the microbial genome database reveals a related group of enzymes (FosX). The genes mlr3345 from Mesorhizobium loti and lmo1702 from Listeria monocytogenes were cloned and the proteins expressed. This heretofore unrecognized group of enzymes is shown to catalyze the Mn(II)-dependent addition of water to C1 of the oxirane. The ability of each enzyme to confer resistance in Escherichia coli is correlated with their catalytic efficiency, such that the M. loti protein confers low resistance while the Listeria enzyme confers very robust resistance. The crystal structure of the FosX from M. loti was solved at a resolution of 1.83 A. The structure reveals an active-site carboxylate (E44) located about 5 A from the expected position of the substrate that appears to be poised to participate in catalysis. Single turnover experiments in H218O and kinetic analysis of the E44G mutant of the FosX enzymes indicate that the carboxylate of E44 acts as a general base in the direct addition of water to 1. The FosX from M. loti also catalyzes the addition of glutathione to the antibiotic. The catalytic promiscuity and low efficiency of the M. loti protein suggest that it may be an intermediate in the evolution of clinically relevant fosfomycin resistance proteins such as the FosX from Listeria monocytogenese.