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Updated: May 22, 2026

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
Published on: November 22, 2014
Co2+/Co+ redox tuning in methyltransferases induced by a conformational change at the axial ligand
Manoj Kumar1, Neeraj Kumar, Hajime Hirao
1Department of Chemistry, University of Louisville, Louisville, Kentucky 40292, USA.
Abstract:
Density functional theory and quantum mechanics/molecular mechanics computations predict cob(I)alamin (Co(+)Cbx), a universal B(12) intermediate state, to be a pentacoordinated square pyramidal complex, which is different from the most widely accepted viewpoint of its tetracoordinated square planar geometry. The square pyramidality of Co(+)Cbx is inspired by the fact that a Co(+) ion, which has a dominant d(8) electronic configuration, forms a distinctive Co(+)--H interaction because of the availability of appropriately oriented filled d orbitals. This uniquely H-bonded Co(+)Cbx may have catalytic relevance in the context of thermodynamically uphill Co(2+)/Co(+) reduction that constitutes an essential component in a large variety of methyltransferases.
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