2P7Q

Crystal structure of E126Q mutant of genomically encoded fosfomycin resistance protein, FosX, from Listeria monocytogenes complexed with MN(II) and 1S,2S-dihydroxypropylphosphonic acid

Summary for 2P7Q

• Entry DOI: 10.2210/pdb2p7q/pdb
• Related: 2P7K 2P7L 2P7M 2P7O 2P7P
• Descriptor: Glyoxalase family protein, MANGANESE (II) ION, [(1S,2S)-1,2-DIHYDROXYPROPYL]PHOSPHONIC ACID, ... (4 entities in total)
• Functional Keywords: fosfomycin resistance protein, mn binding, antibiotic resistance, metal binding protein, hydrolase
• Biological source: Listeria monocytogenes
• Total number of polymer chains: 6
• Total formula weight: 94803.78

Authors

Fillgrove, K.L.,Pakhomova, S.,Schaab, M.,Newcomer, M.E.,Armstrong, R.N. (deposition date: 2007-03-20, release date: 2007-07-17, Last modification date: 2023-08-30)

Primary citation

Fillgrove, K.L.,Pakhomova, S.,Schaab, M.R.,Newcomer, M.E.,Armstrong, R.N.
Structure and Mechanism of the Genomically Encoded Fosfomycin Resistance Protein, FosX, from Listeria monocytogenes.
Biochemistry, 46:8110-8120, 2007

PubMed Abstract: The fosfomycin resistance protein, FosX, catalyzes the hydration of the antibiotic fosfomycin, (1R,2S)-epoxypropylphosphonic acid. Genes encoding the enzyme are found in several pathogenic microorganisms. The structure and mechanism of action of the genomically encoded FosX enzyme from Listeria monocytogenes (FosXLMATCC) obtained from the American Type Culture Collection are reported. The gene harbors 31 point mutations, and as a consequence, the protein differs in 10 amino acid residues from the previously reported FosX encoded in the genome of the EGD strain of L. monocytogenes (FosXLMEGD). The FosXLMATCC enzyme is shown to catalyze the addition of water to the C1 position of the antibiotic with inversion of configuration at C1. The reaction involves Mn(II) activation of the oxirane oxygen and E44 acting as a general base. The structure of the enzyme has been determined from six different crystal forms of the protein. The structures of the enzyme without metal bound are similar but differ in the loop regions. Perhaps the most informative structure is the one with the product bound. This structure shows that the phosphonate group of the product is bound in an orientation that is different than that of fosfomycin bound to the related enzyme, FosA. The implication is that the substrate may also be bound in a different orientation in FosX. A high-resolution structure (1.44 A resolution) of the enzyme reveals a unique conformation in which the C-terminal tail of the protein coordinates to the Mn(II) center via the carboxylate of E126. The kinetic characterization of the E126Q mutant indicates that this conformation of the protein is probably not relevant to the function of the enzyme. Kinetic analysis of mutants of active site residue E44 is consistent with its proposed roll as a general base catalyst in the addition of water to the antibiotic.

PubMed: 17567049
DOI: 10.1021/bi700625p

Experimental method

X-RAY DIFFRACTION (2.4 Å)