Substrate interactions with the nitrogenase active site.
The chemical mechanism for biological cleavage of the N(2) triple bond at ambient pressure and temperature has been the subject of intense study for many years. The site of substrate activation and reduction has been localized to a complex cofactor, called FeMo cofactor, yet until now the complexity of the system has denied information concerning exactly where and how substrates interact with the metal-sulfur framework of the active site. In this Account, we describe a combined genetic, biophysical, and biochemical approach that was used to provide direct and detailed information concerning where alternative alkyne substrates interact with FeMo cofactor during catalysis. The relevance and limitations of this work with respect to N(2) binding and reduction also are discussed.
Dos Santos
Patricia C
PC
Department of Biochemistry, Virginia Tech, Blacksburg, VA 24060, USA.
Igarashi
Robert Y
RY
Lee
Hong-In
HI
Hoffman
Brian M
BM
Seefeldt
Lance C
LC
Dean
Dennis R
DR
D000480:Alkynes / Q000737:chemistry; D001665:Binding Sites; D004578:Electron Spin Resonance Spectroscopy; D008958:Models, Molecular; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020005:Propanols / Q000737:chemistry
D000480:Alkynes; D020005:Propanols; C028255:propargyl alcohol; D009591:Nitrogenase; D009584:Nitrogen