6GL6:
reference: His-ligation to the [4Fe-4S] sub-cluster tunes the catalytic bias of [FeFe] hydrogenase., Rodriguez-Macia P, Kertess L, Burnik J, Birrell JA, Hofmann E, Lubitz W, Happe T, Rudiger O, J Am Chem Soc. 2018 Dec 14. doi: 10.1021/jacs.8b11149. PMID: 30545220

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