Ebright, R.H.; Gunasekeram, A.

Proc. Natl. Acad. Sci. U. S. A. 1990, 87, 2882-2886, 10.1073/pnas.87.8.2882

Escherichia coli catabolite gene activator protein (CAP) is a helix-turn-helix motif sequence-specific DNA binding protein [de Crombrugghe, B., Busby, S. & Buc, H. (1984) Science 224, 831-838; and Pabo, C. & Sauer, R. (1984) Annu. Rev. Biochem. 53, 293-321]. In this work, CAP has been converted into a site-specific DNA cleavage agent by incorporation of the chelator 1,10-phenanthroline at amino acid 10 of the helix-turn-helix motif. [(N-Acetyl-5-amino-1,10-phenanthroline)-Cys178]CAP binds to a 22-base-pair DNA recognition site with Kobs = 1 x 10(8) M-1. In the presence of Cu(II) and reducing agent, [(N-acetyl-5-amino-1,10-phenanthroline)-Cys178]CAP cleaves DNA at four adjacent nucleotides on each DNA strand within the DNA recognition site. The DNA cleavage reaction has been demonstrated using 40-base-pair and 7164-base-pair DNA substrates. The DNA cleavage reaction is not inhibited by dam methylation of the DNA substrate. Such semisynthetic site-specific DNA cleavage agents have potential applications in chromosome mapping, cloning, and sequencing.

Schultz, P.G.

Science 1987, 238, 1401-1403, 10.1126/science.3685986

The relatively nonspecific single-stranded deoxyribonuclease, staphylococcal nuclease, was selectively fused to an oligonucleotide binding site of defined sequence to generate a hybrid enzyme. A cysteine was substituted for Lys116 in the enzyme by oligonucleotide-directed mutagenesis and coupled to an oligonucleotide that contained a 3'-thiol. The resulting hybrid enzyme cleaved single-stranded DNA at sites adjacent to the oligonucleotide binding site.

Arnold, F.H.

J. Am. Chem. Soc. 2019, 141, 19585-19588, 10.1021/jacs.9b11608

Transition-metal catalysis is a powerful tool for the construction of chemical bonds. Here we show that Pseudomonas savastanoi ethylene-forming enzyme, a non-heme iron enzyme, can catalyze olefin aziridination and nitrene C−H insertion, and that these activities can be improved by directed evolution. The nonheme iron center allows for facile modification of the primary coordination sphere by addition of metalcoordinating molecules, enabling control over enzyme activity and selectivity using small molecules.

Happe, T.

Nat. Chem. Biol. 2013, 9, 607-609, 10.1038/Nchembio.1311

Hydrogenases catalyze the formation of hydrogen. The cofactor ('H-cluster') of [FeFe]-hydrogenases consists of a [4Fe-4S] cluster bridged to a unique [2Fe] subcluster whose biosynthesis in vivo requires hydrogenase-specific maturases. Here we show that a chemical mimic of the [2Fe] subcluster can reconstitute apo-hydrogenase to full activity, independent of helper proteins. The assembled H-cluster is virtually indistinguishable from the native cofactor. This procedure will be a powerful tool for developing new artificial H2-producing catalysts.