title: Detection, characterization and evolution of internal repeats in Chitinases of known 3-D structure.
abstract: Chitinase proteins have evolved and diversified almost in all organisms ranging from prokaryotes to eukaryotes. During evolution, internal repeats may appear in amino acid sequences of proteins which alter the structural and functional features. Here we deciphered the internal repeats from Chitinase and characterized the structural similarities between them. Out of 24 diverse Chitinase sequences selected, six sequences (2CJL, 2DSK, 2XVP, 2Z37, 3EBV and 3HBE) did not contain any internal repeats of amino acid sequences. Ten sequences contained repeats of length <50, and the remaining 8 sequences contained repeat length between 50 and 100 residues. Two Chitinase sequences, 1ITX and 3SIM, were found to be structurally similar when analyzed using secondary structure of Chitinase from secondary and 3-Dimensional structure database of Protein Data Bank. Internal repeats of 3N17 and 1O6I were also involved in the ligand-binding site of those Chitinase proteins, respectively. Our analyses enhance our understanding towards the identification of structural characteristics of internal repeats in Chitinase proteins.
authors.affiliation: Department of Plant Science, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Manigandan
authors.initials: M
authors.lastname: Sivaji
authors.affiliation: Department of Plant Science, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Vinoth
authors.initials: V
authors.lastname: Sadasivam
authors.affiliation: Department of Plant Science, Bharathidasan University, Tiruchirappalli, India; Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Jayabalan
authors.initials: J
authors.lastname: Narayanasamy
authors.affiliation: Department of Bioinformatics, Bharathidasan University, Tiruchirappalli, India.
authors.forename: Selvaraj
authors.initials: S
authors.lastname: Samuel
authors.affiliation: Department of Biological Sciences, Wayne State University, Detroit, Michigan, United States of America.
authors.forename: Chuanzhu
authors.initials: C
authors.lastname: Fan
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002688:Chitinases / Q000737:chemistry* / Q000235:genetics*; D019295:Computational Biology; D030562:Databases, Protein; D019143:Evolution, Molecular; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D011485:Protein Binding; D011487:Protein Conformation; D017510:Protein Folding; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D008024:Ligands; D002688:Chitinases