Trace metal requirements
At the heart of enzymes, trace metals are the catalytic site for the essential electron transfers that drive biotic reactions.
Anaerobic archaea (genus Wolframiiraptor) require the trace metal tungsten for growth with corn stover or sugars as substrate.
Anaerobic archaea (Wolframiiraptor) run out of energy without tungsten. Tungsten is an essential cofactor in oxidoreductase enzymes that oxidize aldehyde groups to organic acids. This reaction is coupled to redox cycling of the electron carrier ferredoxin that drives a proton motive force via a membrane-bound hydrogenase.
Zinc fingers are structurally diverse proteins carrying multiple zinc atoms. Image by James H. Thomas, University of Washington