title: Analysis of invariant sequences in 266 complete genomes.
abstract: To date, the complete genome sequences of more than 250 organisms have been determined. This information can now be used to determine whether there exist any invariant sequences that are conserved among all organisms, from bacteria to plants, animals, and humans. The existence of invariant sequences would strongly suggest that these sequences have been inherited unchanged from the last common ancestor of all life, and that they have essential functions. We have developed a new software program to identify invariant sequences conserved among the currently sequenced genomes and applied this analysis to the complete genome sequences of 266 organisms. We have identified 3 invariant DNA sequences longer than or equal to 11 bp and 6 invariant amino acid sequences longer than or equal to 6 aa. The longest invariant DNA sequence, AAGTCGTACAAGGT (15 bp), was found in the 16S/18S rRNA gene. Two 8 aa sequences, GHVDHGKT in IF2 and EF-Tu and DTPGHVDF in EF-G, were the longest invariant amino acid sequences detected. These sequences could be essential elements from the genome of the last common ancestor and may have remained unchanged throughout evolution.
authors.affiliation: Department of Genome Informatics, Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan. ngoto@gen-info.osaka-u.ac.jp
authors.forename: Naohisa
authors.initials: N
authors.lastname: Goto
authors.forename: Ken
authors.initials: K
authors.lastname: Kurokawa
authors.forename: Teruo
authors.initials: T
authors.lastname: Yasunaga
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D019843:Archaeal Proteins / Q000737:chemistry / Q000235:genetics; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence / Q000235:genetics; D017124:Conserved Sequence / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics; D016678:Genome; D020745:Genome, Archaeal; D016680:Genome, Bacterial; D016681:Genome, Fungal; D015894:Genome, Human; D018745:Genome, Plant; D006801:Humans; D014176:Protein Biosynthesis / Q000235:genetics; D011499:Protein Processing, Post-Translational / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000737:chemistry* / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000737:chemistry* / Q000235:genetics; D012338:RNA, Ribosomal, 23S / Q000737:chemistry* / Q000235:genetics; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D012984:Software; D014158:Transcription, Genetic
chemical_list: D019843:Archaeal Proteins; D001426:Bacterial Proteins; D005656:Fungal Proteins; D012336:RNA, Ribosomal, 16S; D012337:RNA, Ribosomal, 18S; D012338:RNA, Ribosomal, 23S