title: Structural relationships among the ribosomal stalk proteins from the three domains of life.
abstract: The GTPase center of the large ribosomal subunit, being a landing platform for translation factors, and regarded as one of the oldest structures in the ribosome, is a universally conserved structure in all domains of life. It is thought that this structure could be responsible for the major breakthrough on the way to the RNA/protein world, because its appearance would have dramatically increased the rate and accuracy of protein synthesis. The major part of this center is recognized as a distinct structural entity, called the stalk. The main functional part of the stalk in all domains of life is composed of small L12/P proteins, which are believed to form an evolutionarily conserved group. However, some data indicate that the bacterial and archaeo/eukaryal proteins are not related to each other structurally, and only a functional relationship may be clearly recognized. To clarify this point, we performed a comprehensive comparative analysis of the L12/P proteins from the three domains of life. The results show that bacterial and archaeo/eukaryal L12/P-proteins are not structurally related and, therefore, might not be linked evolutionarily either. Consequently, these proteins should be regarded as analogous rather than homologous systems and probably appeared on the ribosomal particle in two independent events in the course of evolution.
authors.affiliation: Department of Molecular Biology, Institute of Microbiology and Biotechnology, Maria Curie-Skłodowska University, Akademicka 19, 20-033, Lublin, Poland.
authors.forename: Przemysław
authors.initials: P
authors.lastname: Grela
authors.forename: Pau
authors.initials: P
authors.lastname: Bernadó
authors.forename: Dmitri
authors.initials: D
authors.lastname: Svergun
authors.forename: Jan
authors.initials: J
authors.lastname: Kwiatowski
authors.forename: Dariusz
authors.initials: D
authors.lastname: Abramczyk
authors.forename: Nikodem
authors.initials: N
authors.lastname: Grankowski
authors.forename: Marek
authors.initials: M
authors.lastname: Tchórzewski
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003198:Computer Simulation; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010802:Phylogeny; D017433:Protein Structure, Secondary; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D012269:Ribosomal Proteins