4djd

Crystal structure of folate-free corrinoid iron-sulfur protein (CFeSP) in complex with its methyltransferase (MeTr)

spinqualitylabelsall models 4djd, resolution 2.38Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4djd is a 6 chain structure with sequence from Moorella thermoacetica. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.38Å Ligands: CA, GOL Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function ACSE_MOOTH Methyltransferase that mediates the transfer of a N5-methyl group of (6S)-methyltetrahydrofolate to the 5-methoxybenzimidazolylcobamide cofactor of a corrinoid/Fe-S protein in the anaerobic acetyl-CoA pathway (Wood-Ljungdahl pathway) of carbon monoxide and carbon dioxide fixation. Publication Abstract from PubMed Derivatives of vitamin B(12) are used in methyl group transfer in biological processes as diverse as methionine synthesis in humans and CO(2) fixation in acetogenic bacteria. This seemingly straightforward reaction requires large, multimodular enzyme complexes that adopt multiple conformations to alternately activate, protect and perform catalysis on the reactive B(12) cofactor. Crystal structures determined thus far have provided structural information for only fragments of these complexes, inspiring speculation about the overall protein assembly and conformational movements inherent to activity. Here we present X-ray crystal structures of a complete 220 kDa complex that contains all enzymes responsible for B(12)-dependent methyl transfer, namely the corrinoid iron-sulphur protein and its methyltransferase from the model acetogen Moorella thermoacetica. These structures provide the first three-dimensional depiction of all protein modules required for the activation, protection and catalytic steps of B(12)-dependent methyl transfer. In addition, the structures capture B(12) at multiple locations between its 'resting' and catalytic positions, allowing visualization of the dramatic protein rearrangements that enable methyl transfer and identification of the trajectory for B(12) movement within the large enzyme scaffold. The structures are also presented alongside in crystallo spectroscopic data, which confirm enzymatic activity within crystals and demonstrate the largest known conformational movements of proteins in a crystalline state. Taken together, this work provides a model for the molecular juggling that accompanies turnover and helps explain why such an elaborate protein framework is required for such a simple, yet biologically essential reaction. Visualizing molecular juggling within a B(12)-dependent methyltransferase complex.,Kung Y, Ando N, Doukov TI, Blasiak LC, Bender G, Seravalli J, Ragsdale SW, Drennan CL Nature. 2012 Mar 14. doi: 10.1038/nature10916. PMID:22419154 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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