title: In Silico Identification of Protein Disulfide Isomerase Gene Families in the De Novo Assembled Transcriptomes of Four Different Species of the Genus Conus.
abstract: Small peptides isolated from the venom of the marine snails belonging to the genus Conus have been largely studied because of their therapeutic value. These peptides can be classified in two groups. The largest one is composed by peptides rich in disulfide bonds, and referred to as conotoxins. Despite the importance of conotoxins given their pharmacology value, little is known about the protein disulfide isomerase (PDI) enzymes that are required to catalyze their correct folding. To discover the PDIs that may participate in the folding and structural maturation of conotoxins, the transcriptomes of the venom duct of four different species of Conus from the peninsula of Baja California (Mexico) were assembled. Complementary DNA (cDNA) libraries were constructed for each species and sequenced using a Genome Analyzer Illumina platform. The raw RNA-seq data was converted into transcript sequences using Trinity, a de novo assembler that allows the grouping of reads into contigs without a reference genome. An N50 value of 605 was established as a reference for future assemblies of Conus transcriptomes using this software. Transdecoder was used to extract likely coding sequences from Trinity transcripts, and PDI-specific sequence motif "APWCGHCK" was used to capture potential PDIs. An in silico analysis was performed to characterize the group of PDI protein sequences encoded by the duct-transcriptome of each species. The computational approach entailed a structural homology characterization, based on the presence of functional Thioredoxin-like domains. Four different PDI families were characterized, which are constituted by a total of 41 different gene sequences. The sequences had an average of 65% identity with other PDIs. Using MODELLER 9.14, the homology-based three-dimensional structure prediction of a subset of the sequences reported, showed the expected thioredoxin fold which was confirmed by a "simulated annealing" method.
authors: Departamento de Innovación Biomédica, Centro de Investigación y Estudios Superiores de Ensenada (CICESE), Ensenada, Baja California, México.
authors: Andrea
authors: A
authors: Figueroa-Montiel
authors: Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, Baja California, México.
authors: Marco A
authors: MA
authors: Ramos
authors: Facultad de Ciencias Químicas e Ingeniería, Universidad Autónoma de Baja California, Tijuana, Baja California, México.
authors: Rosa E
authors: RE
authors: Mares
authors: Departamento de Innovación Biomédica, Centro de Investigación y Estudios Superiores de Ensenada (CICESE), Ensenada, Baja California, México.
authors: Salvador
authors: S
authors: Dueñas
authors: Departamento de Innovación Biomédica, Centro de Investigación y Estudios Superiores de Ensenada (CICESE), Ensenada, Baja California, México.
authors: Genaro
authors: G
authors: Pimienta
authors: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
authors: Ernesto
authors: E
authors: Ortiz
authors: Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, México.
authors: Lourival D
authors: LD
authors: Possani
authors: Departamento de Innovación Biomédica, Centro de Investigación y Estudios Superiores de Ensenada (CICESE), Ensenada, Baja California, México.
authors: Alexei F
authors: AF
authors: Licea-Navarro
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D003198:Computer Simulation; D052078:Conus Snail / Q000201:enzymology* / Q000235:genetics*; D020869:Gene Expression Profiling; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000235:genetics*; D017423:Sequence Analysis, RNA; D013045:Species Specificity
chemical_list: D019704:Protein Disulfide-Isomerases