title: Structural motifs of the bacterial ribosomal proteins S20, S18 and S16 that contact rRNA present in the eukaryotic ribosomal proteins S25, S26 and S27A, respectively.
abstract: The majority of constitutive proteins in the bacterial 30S ribosomal subunit have orthologues in Eukarya and Archaea. The eukaryotic counterparts for the remainder (S6, S16, S18 and S20) have not been identified. We assumed that amino acid residues in the ribosomal proteins that contact rRNA are to be constrained in evolution and that the most highly conserved of them are those residues that are involved in forming the secondary protein structure. We aligned the sequences of the bacterial ribosomal proteins from the S20p, S18p and S16p families, which make multiple contacts with rRNA in the Thermus thermophilus 30S ribosomal subunit (in contrast to the S6p family), with the sequences of the unassigned eukaryotic small ribosomal subunit protein families. This made it possible to reveal that the conserved structural motifs of S20p, S18p and S16p that contact rRNA in the bacterial ribosome are present in the ribosomal proteins S25e, S26e and S27Ae, respectively. We suggest that ribosomal protein families S20p, S18p and S16p are homologous to the families S25e, S26e and S27Ae, respectively.
authors.affiliation: Institute for Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090, Russia.
authors.forename: Alexey A
authors.initials: AA
authors.lastname: Malygin
authors.forename: Galina G
authors.initials: GG
authors.lastname: Karpova
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry*; D056890:Eukaryota / Q000235:genetics; D008969:Molecular Sequence Data; D012269:Ribosomal Proteins / Q000737:chemistry*; D054680:Ribosome Subunits, Small, Bacterial / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D016963:Thermus thermophilus / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012269:Ribosomal Proteins; C041184:ribosomal protein S18; C029611:ribosomal protein S20; C096227:ribosomal protein S27a