Assembly and Function of Nitrogenase
Chi-Chung Lee, Martin Tillmann Stiebritz, Yilin Hu,
and Markus Walter Ribbe
Abstract
Nitrogenase is the complex metalloenzyme responsible for the crucial process of
biological nitrogen fixation, in which atmospheric dinitrogen (N 2 ) is converted
into bioavailable ammonia (NH 3 ). This involves the breaking of the inert NN
triple bond, a remarkable feat that is made possible by the unique metal clusters
—the [Fe 8 S 7 ] P-cluster and the [MoFe 7 S 9 C-R-homocitrate] M-cluster. Recent
studies on molybdenum-dependent nitrogenase have greatly extended our
understanding of how both of these fascinating metal clusters are assembled
from common [Fe 4 S 4 ] building blocks, as well as on the series of intriguing
interplay between the proteins that are involved. In parallel, independent
biochemical, spectroscopic, and structural investigations combine to provide
unprecedented insights into the enigmatic mechanism of N 2 reduction. In this
chapter, evidence that led up to these findings will be outlined and discussed in
their respective contexts, followed by a brief perspective on the outlook of the
nitrogenase field.
Keywords
P-cluster Á M-cluster Á K-cluster Á L-cluster Á Carbide insertion Á LoweThorneley scheme Á Distal pathway Á Alternating pathway Á Reductive
elimination Á Belt sulfur atoms
C.-C. Lee (&) Á M. T. Stiebritz Á Y. Hu (&) Á M. W. Ribbe (&)
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
e-mail: chichul@uci.edu
Y. Hu
e-mail: yilinh@uci.edu
M. W. Ribbe
e-mail: mribbe@uci.edu
© Springer Nature Switzerland AG 2021
J. J. G. Moura et al. (eds.), Enzymes for Solving Humankind's Problems,
https://doi.org/10.1007/978-3-030-58315-6_6
155
Chi-Chung Lee, Martin Tillmann Stiebritz, Yilin Hu,
and Markus Walter Ribbe
Abstract
Nitrogenase is the complex metalloenzyme responsible for the crucial process of
biological nitrogen fixation, in which atmospheric dinitrogen (N 2 ) is converted
into bioavailable ammonia (NH 3 ). This involves the breaking of the inert NN
triple bond, a remarkable feat that is made possible by the unique metal clusters
—the [Fe 8 S 7 ] P-cluster and the [MoFe 7 S 9 C-R-homocitrate] M-cluster. Recent
studies on molybdenum-dependent nitrogenase have greatly extended our
understanding of how both of these fascinating metal clusters are assembled
from common [Fe 4 S 4 ] building blocks, as well as on the series of intriguing
interplay between the proteins that are involved. In parallel, independent
biochemical, spectroscopic, and structural investigations combine to provide
unprecedented insights into the enigmatic mechanism of N 2 reduction. In this
chapter, evidence that led up to these findings will be outlined and discussed in
their respective contexts, followed by a brief perspective on the outlook of the
nitrogenase field.
Keywords
P-cluster Á M-cluster Á K-cluster Á L-cluster Á Carbide insertion Á LoweThorneley scheme Á Distal pathway Á Alternating pathway Á Reductive
elimination Á Belt sulfur atoms
C.-C. Lee (&) Á M. T. Stiebritz Á Y. Hu (&) Á M. W. Ribbe (&)
Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, USA
e-mail: chichul@uci.edu
Y. Hu
e-mail: yilinh@uci.edu
M. W. Ribbe
e-mail: mribbe@uci.edu
© Springer Nature Switzerland AG 2021
J. J. G. Moura et al. (eds.), Enzymes for Solving Humankind's Problems,
https://doi.org/10.1007/978-3-030-58315-6_6
155