Structural biology. Division of labor in transhydrogenase by alternating proton translocation and hydride transfer.
Science
; 347(6218): 178-81, 2015 Jan 09.
Article
em En
| MEDLINE
| ID: mdl-25574024
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.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Prótons
/
NADP Trans-Hidrogenases
Idioma:
En
Revista:
Science
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Estados Unidos