Assembly scaffold NifEN: A structural and functional homolog of the nitrogenase catalytic component

Journal Article · Tue Aug 09 00:00:00 EDT 2016 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.1609574113· OSTI ID:1288984

Fay, Aaron W. ^[1]; Blank, Michael A. ^[2]; Rebelein, Johannes G. ^[1]; Lee, Chi Chung ^[1]; Ribbe, Markus W. ^[3]; Hedman, Britt ^[4]; Hodgson, Keith O. ^[2]; Hu, Yilin ^[1]

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1. Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900,
2. Department of Chemistry, Stanford University, Stanford, CA 94305,
3. Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900,, Department of Chemistry, University of California, Irvine, CA 92697-2025,
4. Stanford Synchrotron Radiation Lightsource, Stanford Linear Accelerator Center, Stanford University, Menlo Park, CA 94025

Significance This work provides direct evidence for the formation of an M-cluster on the assembly scaffold NifEN, establishing NifEN as the second known protein that houses a nitrogenase cofactor. A “half-on, half-off” scheme of cofactor biosynthesis can be proposed based on the outcome of this study, which suggests an asymmetric nature of the assembly sites in the seemingly equivalent αβ-halves of NifEN and a coordination of various biosynthetic events via a unique conformational switch on/off mechanism. The comparable substrate-reducing capabilities of NifEN and NifDK establish the former as a structural and functional homolog of the latter, providing a proof-of-concept for the feasibility of probing key catalytic features of NifDK via reconstruction of a NifDK equivalent on the basis of a “simplified” template, NifEN.

• Sponsoring Organization: USDOE
• Grant/Contract Number: AC02-76SF00515
• OSTI ID: 1288984
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Vol. 113 Journal Issue: 34; ISSN 0027-8424
• Publisher: Proceedings of the National Academy of Sciences
• Country of Publication: United States
• Language: English