Journal of Proteomics & Bioinformatics
Open Access

Abstract

Evolutionary Analysis of CRISPRs in Archaea: An Evidence for Horizontal Gene Transfer

Anupama S, Aswathy Rajan MP, Gurusaran M, Radha P, Dinesh Kumar KS, Chitra R, Hima Vyshanavi AM and Sekar K

Akin to the eukaryotic immune system, prokaryotes harbor CRISPRs, a lineup of DNA direct repeats and spacers to foster immunity against the invading phages and plasmids. A CRISPR (Clustered Regularly Interspaced Short Palindrome Repeats) unit found within the genome of an organism consists of an array of repeating sequences interspaced by unique spacers and is associated with special genes that reside adjacent to the array. The spacer sequences are nucleotide fragments integrated from an invading organism. The comparative genomic analysis of CRISPR sequences affirms huge variation within the CRISPR–CAS systems among different prokaryotes. Here, an analysis of the complete archaeal species is directed for their CRISPR sequences along with a case study. The phylogenetic analysis sketched from the CRISPR sequences signifies a harmony along the direct repeats of the analyzed organisms with no trace of spacer similarity. Further, novel CRISPR elements are procured, aside from those formerly present in the database. The CRISPRs are then subjected for local alignment using BLAST to ensure whether any of the sequences showed similarity with the human and viral genomes available in NCBI.