Yeast strains with N-terminally truncated ribosomal protein S5: implications for the evolution, structure and function of the Rps5/Rps7 proteins.
Ribosomal protein (rp)S5 belongs to the family of the highly conserved rp's that contains rpS7 from prokaryotes and rpS5 from eukaryotes. Alignment of rpS5/rpS7 from metazoans (Homo sapiens), fungi (Saccharomyces cerevisiae) and bacteria (Escherichia coli) shows that the proteins contain a conserved central/C-terminal core region and possess variable N-terminal regions. Yeast rpS5 is 69 amino acids (aa) longer than the E. coli rpS7 protein; and human rpS5 is 48 aa longer than the rpS7, respectively. To investigate the function of the yeast rpS5 and in particular the role of its N-terminal region, we obtained and characterized yeast strains in which the wild-type yeast rpS5 was replaced by its truncated variants, lacking 13, 24, 30 and 46 N-terminal amino acids, respectively. All mutant yeast strains were viable and displayed only moderately reduced growth rates, with the exception of the strain lacking 46 N-terminal amino acids, which had a doubling time of about 3 h. Biochemical analysis of the mutant yeast strains suggests that the N-terminal part of the eukaryotic and, in particular, yeast rpS5 may impact the ability of 40S subunits to function properly in translation and affect the efficiency of initiation, specifically the recruitment of initiation factors eIF3 and eIF2.
Lumsden
Thomas
T
Center for Gene Regulation in Health and Disease, Department of Biological, Geological and Environmental Sciences, Cleveland State University, 2121 Euclid Avenue, Cleveland, OH 44115, USA.
Bentley
Amber A
AA
Beutler
William
W
Ghosh
Arnab
A
Galkin
Oleksandr
O
Komar
Anton A
AA
D000595:Amino Acid Sequence; D029968:Escherichia coli Proteins / Q000737:chemistry; D015852:Eukaryotic Initiation Factor-2 / Q000378:metabolism; D039621:Eukaryotic Initiation Factor-3 / Q000378:metabolism; D019143:Evolution, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D010442:Peptide Chain Initiation, Translational; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D054682:Ribosome Subunits, Small, Eukaryotic / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid
D029968:Escherichia coli Proteins; D015852:Eukaryotic Initiation Factor-2; D039621:Eukaryotic Initiation Factor-3; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C030831:ribosomal protein S5; C037442:ribosomal protein S7