Tracing the incorporation of the "ninth sulfur" into the nitrogenase cofactor precursor with selenite and tellurite

Kazuki Tanifuji; Andrew J Jasniewski; David Villarreal; Martin T Stiebritz; Chi Chung Lee; Jarett Wilcoxen; Yasuhiro Okhi; Ruchira Chatterjee; Isabel Bogacz; Junko Yano; Jan Kern; Britt Hedman; Keith O Hodgson; R David Britt; Yilin Hu; Markus W Ribbe

doi:10.1038/s41557-021-00799-8

Tracing the incorporation of the "ninth sulfur" into the nitrogenase cofactor precursor with selenite and tellurite

Nat Chem. 2021 Dec;13(12):1228-1234. doi: 10.1038/s41557-021-00799-8. Epub 2021 Oct 11.

Authors

Kazuki Tanifuji^{1

2}, Andrew J Jasniewski¹, David Villarreal³, Martin T Stiebritz¹, Chi Chung Lee¹, Jarett Wilcoxen⁴, Yasuhiro Okhi², Ruchira Chatterjee⁵, Isabel Bogacz⁵, Junko Yano⁵, Jan Kern⁵, Britt Hedman⁶, Keith O Hodgson^{6

7}, R David Britt⁸, Yilin Hu⁹, Markus W Ribbe^{10

11}

Affiliations

¹ Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA.
² International Research Center for Elements Science, Institute for Chemical Research, Kyoto University, Kyoto, Japan.
³ Department of Chemistry, University of California, Davis, Davis, CA, USA.
⁴ Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee, WI, USA.
⁵ Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
⁶ Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, USA.
⁷ Department of Chemistry, Stanford University, Stanford, CA, USA.
⁸ Department of Chemistry, University of California, Davis, Davis, CA, USA. mribbe@uci.edu.
⁹ Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA. yilinh@uci.edu.
¹⁰ Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, USA. rdbritt@ucdavis.edu.
¹¹ Department of Chemistry, University of California, Irvine, Irvine, CA, USA. rdbritt@ucdavis.edu.

Abstract

Molybdenum nitrogenase catalyses the reduction of N₂ to NH₃ at its cofactor, an [(R-homocitrate)MoFe₇S₉C] cluster synthesized via the formation of a [Fe₈S₉C] L-cluster prior to the insertion of molybdenum and homocitrate. We have previously identified a [Fe₈S₈C] L*-cluster, which is homologous to the core structure of the L-cluster but lacks the 'ninth sulfur' in the belt region. However, direct evidence and mechanistic details of the L*- to L-cluster conversion upon 'ninth sulfur' insertion remain elusive. Here we trace the 'ninth sulfur' insertion using SeO₃^2- and TeO₃^2- as 'labelled' SO₃^2-. Biochemical, electron paramagnetic resonance and X-ray absorption spectroscopy/extended X-ray absorption fine structure studies suggest a role of the 'ninth sulfur' in cluster transfer during cofactor biosynthesis while revealing the incorporation of Se^2-- and Te^2--like species into the L-cluster. Density functional theory calculations further point to a plausible mechanism involving in situ reduction of SO₃^2- to S^2-, thereby suggesting the utility of this reaction to label the catalytically important belt region for mechanistic investigations of nitrogenase.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Archaeal Proteins / chemistry
Coenzymes / chemistry*
Density Functional Theory
Electron Spin Resonance Spectroscopy
Iron-Sulfur Proteins / chemistry*
Methanosarcina / enzymology
Models, Chemical
Nitrogenase / chemistry*
Selenious Acid / chemistry*
Sulfur / chemistry*
Tellurium / chemistry*
X-Ray Absorption Spectroscopy

Substances

Archaeal Proteins
Coenzymes
Iron-Sulfur Proteins
Sulfur
Nitrogenase
Selenious Acid
tellurous acid
Tellurium

Abstract

Publication types

MeSH terms

Substances

Grants and funding