Efficient electron transfer in a protein network lacking specific interactions.
J Am Chem Soc
; 133(42): 16861-7, 2011 Oct 26.
Article
en En
| MEDLINE
| ID: mdl-21916462
ABSTRACT
In many biochemical processes, proteins need to bind partners amidst a sea of other molecules. Generally, partner selection is achieved by formation of a single-orientation complex with well-defined, short-range interactions. We describe a protein network that functions effectively in a metabolic electron transfer process but lacks such specific interactions. The soil bacterium Paracoccus denitrificans oxidizes a variety of compounds by channeling electrons into the main respiratory pathway. Upon conversion of methylamine by methylamine dehydrogenase, electrons are transported to the terminal oxidase to reduce molecular oxygen. Steady-state kinetic measurements and NMR experiments demonstrate a remarkable number of possibilities for the electron transfer, involving the cupredoxin amicyanin as well as four c-type cytochromes. The observed interactions appear to be governed exclusively by the electrostatic nature of each of the proteins. It is concluded that Paracoccus provides a pool of cytochromes for efficient electron transfer via weak, ill-defined interactions, in contrast with the view that functional biochemical interactions require well-defined molecular interactions. It is proposed that the lack of requirement for specificity in these interactions might facilitate the integration of new metabolic pathways.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas
/
Transporte de Electrón
/
Modelos Biológicos
Idioma:
En
Revista:
J Am Chem Soc
Año:
2011
Tipo del documento:
Article
País de afiliación:
Italia