title: Assessing computational amino acid beta-turn propensities with a phage-displayed combinatorial library and directed evolution.
abstract: Structure propensities of amino acids are important determinants in guiding proteins' local and global structure formation. We constructed a phage display library--a hexa-HIS tag upstream of a CXXC (X stands for any of the 20 natural amino acids) motif appending N-terminal to the minor capsid protein pIII of M13KE filamentous phage--and developed a novel directed-evolution procedure to select for amino acid sequences forming increasingly stable beta-turns in the disulfide-bridged CXXC motif. The sequences that emerged from the directed-evolution cycles were in good agreement with type II beta-turn propensities derived from surveys of known protein structures, in particular, Pro-Gly forming a type II beta-turn. The agreement strongly supported the notion that beta-turn formation plays an active role in initiating local structure folding in proteins.
authors.affiliation: Genomics Research Center, Academia Sinica, 128 Academia Road, Section 2, Taipei 115, Taiwan.
authors.forename: Hung-Ju
authors.initials: HJ
authors.lastname: Hsu
authors.forename: Hong-Ju
authors.initials: HJ
authors.lastname: Chang
authors.forename: Hung-Pin
authors.initials: HP
authors.lastname: Peng
authors.forename: Shan-Sheng
authors.initials: SS
authors.lastname: Huang
authors.forename: Ming-Yen
authors.initials: MY
authors.lastname: Lin
authors.forename: An-Suei
authors.initials: AS
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D017104:Bacteriophage M13 / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D036022:Capsid Proteins; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019020:Directed Molecular Evolution; D005240:Feasibility Studies; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019151:Peptide Library; D017510:Protein Folding; D017433:Protein Structure, Secondary; D014760:Viral Fusion Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D019151:Peptide Library; D014760:Viral Fusion Proteins