NifB-dependent in vitro synthesis of the iron-molybdenum cofactor of nitrogenase

CURATTI LEONARDO; LUDDEN PAUL; RUBIO LUIS

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA

Año: 2006 vol. 103 p. 5297 - 5301

0027-8424

Biological nitrogen fixation, an essential process of the biogeochemical nitrogen cycle that supports life on Earth, is catalyzed by the nitrogenase enzyme. The nitrogenase active site contains an iron and molybdenum cofactor (FeMo-co) composed of 7Fe-9S-Mo-homocitrate and one not-yet-identified atom, which probably is the most complex [Fe-S] cluster in nature. Here, we show the in vitro synthesis of FeMo-co from its simple constituents, Fe, S, Mo, and homocitrate. The in vitro FeMo-co synthesis requires purified NifB and depends on S-adenosylmethionine, indicating that radical chemistry is required during FeMo-co assembly.