Cluster-selective ⁵⁷Fe labeling of a Twitch-domain-containing radical SAM enzyme.

ABSTRACT: ⁵⁷Fe-specific techniques such as Mössbauer spectroscopy are invaluable tools in mechanistic studies of Fe-S proteins. However, they remain underutilized for proteins that bind multiple Fe-S clusters because such proteins are typically uniformly enriched with ⁵⁷Fe. As a result, it can be unclear which spectroscopic responses derive from which cluster, and this in turn obscures the chemistry that takes place at each cluster. Herein, we report a facile method for cluster-selective ⁵⁷Fe enrichment based on exchange between the protein's Fe-S clusters and exogenous Fe ions. Through a combination of inductively coupled plasma mass spectrometric and ⁵⁷Fe Mössbauer spectroscopic analysis, we show that, of the two [Fe₄S₄] clusters in

SUBMITTER: Namkoong G 

PROVIDER: S-EPMC10337720 | biostudies-literature | 2023 Jul

REPOSITORIES: biostudies-literature