1v9a
Crystal structure of Uroporphyrin-III C-methyl transferase from Thermus thermophilus complexed with S-adenyl homocysteine
| |||||||
| , resolution 2.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | and | ||||||
| Activity: | Uroporphyrinogen-III C-methyltransferase, with EC number 2.1.1.107 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
OverviewOverview
Uroporphyrinogen-III C-methyltransferase from Thermus thermophilus is a multifunctional protein responsible for two of the eight S-adenosyl-methionine-dependent methylations of the corrin ring during vitamin B(12) synthesis. The structure of this protein has been solved to 2.0 A resolution in both the apo and cofactor-bound form. The monomer consists of two domains, A and B, each consisting of a five-stranded beta-sheet and two or three alpha-helices, with the cofactor bound at the interface. The biological unit is the dimer found in the asymmetric unit. This dimer is related by a non-crystallographic twofold such that two B domains combine to form a long ten-stranded beta-sheet. When compared with solved related structures, this structure shows clear differences in the region involved in cofactor and substrate binding, affirming the role of several previously implicated residues and questioning others. The solved related structures are characterized by an exposed active site. The T. thermophilus structure has this site restricted by the interaction of a flexible loop structure with a highly conserved residue, suggesting a mechanistic role. This structure represents the ;closed' form of the protein.
About this StructureAbout this Structure
1V9A is a Single protein structure of sequence from Thermus thermophilus. Full crystallographic information is available from OCA.
ReferenceReference
Structure of a closed-form uroporphyrinogen-III C-methyltransferase from Thermus thermophilus., Rehse PH, Kitao T, Tahirov TH, Acta Crystallogr D Biol Crystallogr. 2005 Jul;61(Pt 7):913-9. Epub 2005, Jun 24. PMID:15983414
Page seeded by OCA on Thu Mar 20 14:42:30 2008