6RVH

NADH-dependent Coenzyme A Disulfide Reductase soaked with Menadione

Summary for 6RVH

• Entry DOI: 10.2210/pdb6rvh/pdb
• Descriptor: NADH oxidase, FLAVIN-ADENINE DINUCLEOTIDE, COENZYME A, ... (5 entities in total)
• Functional Keywords: coenzyme a disulfide reductase, nadh oxidation, flavoprotein, menadione, oxidoreductase
• Biological source: Thermus thermophilus
• Total number of polymer chains: 4
• Total formula weight: 198579.88

Authors

Koepke, J.,Preu, J. (deposition date: 2019-05-31, release date: 2019-09-25, Last modification date: 2024-01-24)

Primary citation

Lencina, A.M.,Koepke, J.,Preu, J.,Muenke, C.,Gennis, R.B.,Michel, H.,Schurig-Briccio, L.A.
Characterization and X-ray structure of the NADH-dependent coenzyme A disulfide reductase from Thermus thermophilus.
Biochim Biophys Acta Bioenerg, 1860:148080-148080, 2019

PubMed Abstract: The crystal structure of the enzyme previously characterized as a type-2 NADH:menaquinone oxidoreductase (NDH-2) from Thermus thermophilus has been solved at a resolution of 2.9 Å and revealed that this protein is, in fact, a coenzyme A-disulfide reductase (CoADR). Coenzyme A (CoASH) replaces glutathione as the major low molecular weight thiol in Thermus thermophilus and is maintained in the reduced state by this enzyme (CoADR). Although the enzyme does exhibit NADH:menadione oxidoreductase activity expected for NDH-2 enzymes, the specific activity with CoAD as an electron acceptor is about 5-fold higher than with menadione. Furthermore, the crystal structure contains coenzyme A covalently linked Cys44, a catalytic intermediate (Cys44-S-S-CoA) reduced by NADH via the FAD cofactor. Soaking the crystals with menadione shows that menadione can bind to a site near the redox active FAD, consistent with the observed NADH:menadione oxidoreductase activity. CoADRs from other species were also examined and shown to have measurable NADH:menadione oxidoreductase activity. Although a common feature of this family of enzymes, no biological relevance is proposed. The CoADR from T. thermophilus is a soluble homodimeric enzyme. Expression of the recombinant TtCoADR at high levels in E. coli results in a small fraction that co-purifies with the membrane fraction, which was used previously to isolate the enzyme wrongly identified as a membrane-bound NDH-2. It is concluded that T. thermophilus does not contain an authentic NDH-2 component in its aerobic respiratory chain.

PubMed: 31520616
DOI: 10.1016/j.bbabio.2019.148080

Experimental method

X-RAY DIFFRACTION (3 Å)