title: Evolution of iron(II)-finger peptides by using a bipyridyl amino acid.
abstract: We report the engineering of zinc-finger-like motifs containing the unnatural amino acid (2,2'-bipyridin-5-yl)alanine (Bpy-Ala). A phage-display library was constructed in which five residues in the N-terminal finger of zif268 were randomized to include both canonical amino acids and Bpy-Ala. Panning of this library against a nine-base-pair DNA binding site identified several Bpy-Ala-containing functional Zif268 mutants. These mutants bind the Zif268 recognition site with affinities comparable to that of the wild-type protein. Further characterization indicated that the mutant fingers bind low-spin Fe(II) rather than Zn(II) . This work demonstrates that an expanded genetic code can lead to new metal ion binding motifs that can serve as structural, catalytic, or regulatory elements in proteins.
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Mingchao
authors.initials: M
authors.lastname: Kang
authors.affiliation: Department of Chemistry, Stanford University, 333 Campus Drive, Stanford CA 94305.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Light
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Hui-Wang
authors.initials: HW
authors.lastname: Ai
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Weijun
authors.initials: W
authors.lastname: Shen
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Chan Hyuk
authors.initials: CH
authors.lastname: Kim
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Peng R
authors.initials: PR
authors.lastname: Chen
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Hyun Soo
authors.initials: HS
authors.lastname: Lee
authors.affiliation: Department of Chemistry, Stanford University, 333 Campus Drive, Stanford CA 94305.
authors.forename: Edward I
authors.initials: EI
authors.lastname: Solomon
authors.affiliation: Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Rd, La Jolla, CA 92037.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Schultz
mesh_terms: D015082:2,2'-Dipyridyl / Q000737:chemistry*; D000409:Alanine / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D056831:Coordination Complexes / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000378:metabolism; D005296:Ferrous Compounds / Q000737:chemistry*; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D010957:Plasmids / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D056831:Coordination Complexes; D004268:DNA-Binding Proteins; D005296:Ferrous Compounds; D019151:Peptide Library; D010455:Peptides; D015082:2,2'-Dipyridyl; D004247:DNA; D000409:Alanine
keywords: amino acids; bipyridyl complexes; iron; phage display; zinc finger engineering