4O9U

Mechanism of transhydrogenase coupling proton translocation and hydride transfer

Summary for 4O9U

• Entry DOI: 10.2210/pdb4o9u/pdb
• Descriptor: NAD(P) transhydrogenase subunit alpha 2, NAD(P) transhydrogenase subunit beta, NAD/NADP transhydrogenase alpha subunit 1, ... (5 entities in total)
• Functional Keywords: nicotinamide nucleotide transhydrogenase, couples proton motive, hydride transfer, holo-transhydrogease from thermus thermophilus assembled from subunits alpha1, alpha2, truncated beta, and domain iii as a dimer, respiratory proton pump enzyme forming cytosolic nadp(h), protons and nad(h), nadp(h), proton translocation and hydride transfer, periplasmic membrane and cytosol, membrane protein
• Biological source: Thermus thermophilus; More
• Total number of polymer chains: 6
• Total formula weight: 201374.27

Authors

Leung, J.H.,Yamaguchi, M.,Moeller, A.,Schurig-Briccio, L.A.,Gennis, R.B.,Potter, C.S.,Carragher, B.,Stout, C.D. (deposition date: 2014-01-02, release date: 2015-01-28, Last modification date: 2024-03-13)

Primary citation

Leung, J.H.,Schurig-Briccio, L.A.,Yamaguchi, M.,Moeller, A.,Speir, J.A.,Gennis, R.B.,Stout, C.D.
Structural biology. Division of labor in transhydrogenase by alternating proton translocation and hydride transfer.
Science, 347:178-181, 2015

PubMed Abstract: NADPH/NADP(+) (the reduced form of NADP(+)/nicotinamide adenine dinucleotide phosphate) homeostasis is critical for countering oxidative stress in cells. Nicotinamide nucleotide transhydrogenase (TH), a membrane enzyme present in both bacteria and mitochondria, couples the proton motive force to the generation of NADPH. We present the 2.8 Å crystal structure of the transmembrane proton channel domain of TH from Thermus thermophilus and the 6.9 Å crystal structure of the entire enzyme (holo-TH). The membrane domain crystallized as a symmetric dimer, with each protomer containing a putative proton channel. The holo-TH is a highly asymmetric dimer with the NADP(H)-binding domain (dIII) in two different orientations. This unusual arrangement suggests a catalytic mechanism in which the two copies of dIII alternatively function in proton translocation and hydride transfer.

PubMed: 25574024
DOI: 10.1126/science.1260451

Experimental method

X-RAY DIFFRACTION (6.926 Å)