Cofactor maturase NifEN: A prototype ancient nitrogenase?
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38865457.
- Also identified by DOI 10.1126/sciadv.ado6169 and PMC identifier 11168457.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Nitrogenase plays a key role in the global nitrogen cycle; yet, the evolutionary history of nitrogenase and, particularly, the sequence of appearance between the homologous, yet distinct NifDK (the catalytic component) and NifEN (the cofactor maturase) of the extant molybdenum nitrogenase, remains elusive. Here, we report the ability of NifEN to reduce N<sub>2</sub> at its surface-exposed L-cluster ([Fe<sub>8</sub>S<sub>9</sub>C]), a structural/functional homolog of the M-cluster (or cofactor; [(<i>R</i>-homocitrate)MoFe<sub>7</sub>S<sub>9</sub>C]) of NifDK. Furthermore, we demonstrate the ability of the L-cluster-bound NifDK to mimic its NifEN counterpart and enable N<sub>2</sub> reduction. These observations, coupled with phylogenetic, ecological, and mechanistic considerations, lead to the proposal of a NifEN-like, L-cluster-carrying protein as an ancient nitrogenase, the exploration of which could shed crucial light on the evolutionary origin of nitrogenase and related enzymes.
Medical subject headings
- Nitrogenase