Assessing the role of redox carriers in the reduction of CO by the oxo-acid: ferredoxin oxidoreductase superfamily.

The oxo-acid:ferredoxin oxidoreductase (OFOR) superfamily of enzymes are responsible for the reversible interconversion of CO and oxo-acids, using CoA-derivatives as co-substrates, and requiring redox equivalents in the form of a soluble redox-carrier protein ferredoxin (Fd). Ultimately, these enzymes are responsible for the reduction of CO to form pyruvate (in the case of PFOR) and oxo-glutarate (in the case of OGOR), by the reductive carboxylation reaction of acetyl-CoA and succinyl-CoA, respectively. The nature and kind of Fd that is the best redox-carrier to support the reductive reaction has been poorly studied to date.

Crystal structure and spectroscopic properties of aqua-dichlorido-{1,1'-[(pyridine-2,6-diyl-κ)bis(methyl-ene)]bis-(4-butyl-4,5-di-hydro-1-1,2,4-triazole-5-thione-κ )}cobalt(II).

The structure of the title compound, [CoCl(CHNS)(HO)], at 173 K has monoclinic (2/) symmetry. We report here the synthesis, single-crystal structure, electrospray mass spectrum and NMR spectroscopy of a new six-coordinate cobalt(II) pincer complex. The pincer ligand, in this complex, which is novel, coordinates three nitro-gen atoms (two triazole and one pyridine).

Preparation of SNS Cobalt(II) Pincer Model Complexes of Liver Alcohol Dehydrogenase.

Chemical model complexes are prepared to represent the active site of an enzyme. In this protocol, a family of tridentate pincer ligand precursors (each possessing two sulfur and one nitrogen donor atom functionalities (SNS) and based on bis-imidazole or bis-triazole compounds) are metallated with CoCl2·6H2O to afford tridentate SNS pincer cobalt(II) complexes. Preparation of the cobalt(II) model complexes for liver alcohol dehydrogenase is facile.

Spectroscopic and Electrochemical Characterization of the Mycofactocin Biosynthetic Protein, MftC, Provides Insight into Its Redox Flipping Mechanism.

Mycofactocin is a putative redox cofactor and is classified as a ribosomally synthesized and post-translationally modified peptide (RiPP). Some RiPP natural products, including mycofactocin, rely on a radical S-adenosylmethionine (RS, SAM) protein to modify the precursor peptide. Mycofactocin maturase, MftC, is a unique RS protein that catalyzes the oxidative decarboxylation and C-C bond formation on the precursor peptide MftA.

Metalloprotein switches that display chemical-dependent electron transfer in cells.

Biological electron transfer is challenging to directly regulate using environmental conditions. To enable dynamic, protein-level control over energy flow in metabolic systems for synthetic biology and bioelectronics, we created ferredoxin logic gates that utilize transcriptional and post-translational inputs to control energy flow through a synthetic electron transfer pathway that is required for bacterial growth. These logic gates were created by subjecting a thermostable, plant-type ferredoxin to backbone fission and fusing the resulting fragments to a pair of proteins that self-associate, a pair of proteins whose association is stabilized by a small molecule, and to the termini of a ligand-binding domain.