title: High-performance computational analysis and peptide screening from databases of cyclotides from poaceae.
abstract: Cyclotides are a family of head-to-tail cyclized peptides containing three conserved disulfide bonds, in a structural scaffold also known as a cyclic cysteine knot. Due to the high degree of cysteine conservation, novel members from this peptide family can be identified in protein databases through a search through regular expression (REGEX). In this work, six novel cyclotide-like precursors from the Poaceae were identified from NCBI's non-redundant protein database by the use of REGEX. Two out of six sequences (named Zea mays L and M) showed an Asp residue in the C-terminal, which indicated that they could be cyclic. Gene expression in maize tissues was investigated, showing that the previously described cyclotide-like Z. mays J is expressed in the roots. According to molecular dynamics, the structure of Z. mays J seems to be stable, despite the putative absence of cyclization. As regards cyclotide evolution, it was hypothesized that this is an outcome from convergent evolution and/or horizontal gene transfer. The results showed that peptide screening from databases should be performed periodically in order to include novel sequences, which are deposited as the databases grow. Indeed, the advances in computational and experimental methods will together help to answer key questions and reach new horizons in defense-related peptide identification.
authors.affiliation: Centro De Análises Proteômicas E Bioquímicas, Pós-Graduação Em Ciências Genômicas E Biotecnologia Universidade Católica De Brasília, Brasília-DF, Brazil.
authors.forename: William F
authors.initials: WF
authors.lastname: Porto
authors.affiliation: Centro De Análises Proteômicas E Bioquímicas, Pós-Graduação Em Ciências Genômicas E Biotecnologia Universidade Católica De Brasília, Brasília-DF, Brazil.
authors.forename: Vivian J
authors.initials: VJ
authors.lastname: Miranda
authors.affiliation: Centro De Análises Proteômicas E Bioquímicas, Pós-Graduação Em Ciências Genômicas E Biotecnologia Universidade Católica De Brasília, Brasília-DF, Brazil.
authors.forename: Michelle F S
authors.initials: MF
authors.lastname: Pinto
authors.affiliation: Centro De Análises Proteômicas E Bioquímicas, Pós-Graduação Em Ciências Genômicas E Biotecnologia Universidade Católica De Brasília, Brasília-DF, Brazil.
authors.forename: Stephan M
authors.initials: SM
authors.lastname: Dohms
authors.affiliation: Centro De Análises Proteômicas E Bioquímicas, Pós-Graduação Em Ciências Genômicas E Biotecnologia Universidade Católica De Brasília, Brasília-DF, Brazil.|S-Inova Biotech, Pos Graduação em Biotecnologia, Universidade Catolica Dom Bosco, Campo Grande MS, Brazil.
authors.forename: Octavio L
authors.initials: OL
authors.lastname: Franco
mesh_terms: D000595:Amino Acid Sequence; D047169:Cyclotides / Q000737:chemistry*; D030562:Databases, Protein; D056004:Molecular Dynamics Simulation; D006109:Poaceae / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid; D003313:Zea mays / Q000737:chemistry
chemical_list: D047169:Cyclotides
keywords: data mining; molecular dynamics; phylogenetic analysis; regular expression