3T0C: Crystal Structure Of Streptococcus Mutans Mete Complexed With Zinc

Cobalamin-independent methionine synthase (MetE) catalyzes the direct transfer of a methyl group from methyltetrahydrofolate to l-homocysteine to form methionine. Previous studies have shown that the MetE active site coordinates a zinc atom, which is thought to act as a Lewis acid and plays a role in the activation of thiol. Extended X-ray absorption fine structure studies and mutagenesis experiments identified the zinc-binding site in MetE from Escherichia coli. Further structural investigations of MetE from Thermotoga maritima lead to the proposition of two models: "induced fit" and "dynamic equilibrium", to account for the catalytic mechanisms of MetE. Here, we present crystal structures of oxidized and zinc-replete MetE from Streptococcus mutans at the physiological pH. The structures reveal that zinc is mobile in the active center and has the possibility to invert even in the absence of homocysteine. These structures provide evidence for the dynamic equilibrium model.
PDB ID: 3T0CDownload
MMDB ID: 92414
PDB Deposition Date: 2011/7/19
Updated in MMDB: 2011/09
Experimental Method:
x-ray diffraction
Resolution: 2.19  Å
Source Organism:
Similar Structures:
Biological Unit for 3T0C: monomeric; determined by author and by software (PISA)
Molecular Components in 3T0C
Label Count Molecule
Protein (1 molecule)
5-methyltetrahydropteroyltriglutamate--homocysteine Methyltransferase(Gene symbol: metE)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB