title: In vivo formation of Plasmodium falciparum ribosomal stalk - a unique mode of assembly without stable heterodimeric intermediates.
abstract: BACKGROUND
  The ribosomal stalk composed of P-proteins constitutes a structure on the large ribosomal particle responsible for recruitment of translation factors and stimulation of factor-dependent GTP hydrolysis during translation. The main components of the stalk are P-proteins, which form a pentamer. Despite the conserved basic function of the stalk, the P-proteins do not form a uniform entity, displaying heterogeneity in the primary structure across the eukaryotic lineage. The P-proteins from protozoan parasites are among the most evolutionarily divergent stalk proteins.
  
  
  METHODS
  We have assembled P-stalk complex of Plasmodium falciparum in vivo in bacterial system using tricistronic expression cassette and provided its characteristics by biochemical and biophysical methods.
  
  
  RESULTS
  All three individual P-proteins, namely uL10/P0, P1 and P2, are indispensable for acquisition of a stable structure of the P stalk complex and the pentameric uL10/P0-(P1-P2)₂form represents the most favorable architecture for parasite P-proteins.
  
  
  CONCLUSIONS
  The formation of P. falciparum P-stalk is driven by trilateral interaction between individual elements which represents unique mode of assembling, without stable P1-P2 heterodimeric intermediate.
  
  
  CONCLUSIONS
  On the basis of our mass-spectrometry analysis supported by the bacterial two-hybrid assay and biophysical analyses, a unique pathway of the parasite stalk assembling has been proposed. We suggest that the absence of P1/P2 heterodimer, and the formation of a stable pentamer in the presence of all three proteins, indicate a one-step formation to be the main pathway for the vital ribosomal stalk assembly, whereas the P2 homo-oligomer may represent an off-pathway product with physiologically important nonribosomal role.
authors.affiliation: Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
authors.forename: Leszek
authors.initials: L
authors.lastname: Wawiórka
authors.affiliation: Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Krokowski
authors.affiliation: Department of Chemistry, University of Oxford, South Parks Rd, Oxford OX1 3QZ, UK.
authors.forename: Yuliya
authors.initials: Y
authors.lastname: Gordiyenko
authors.affiliation: Department of Protein Biotechnology, Faculty of Biotechnology, University of Wroclaw, Tamka 2, 50-137 Wroclaw, Poland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Krowarsch
authors.affiliation: Department of Chemistry, University of Oxford, South Parks Rd, Oxford OX1 3QZ, UK.
authors.forename: Carol V
authors.initials: CV
authors.lastname: Robinson
authors.affiliation: Department of Obstetrics & Gynecology, Faculty of Medicine, AlKaser Street, University of Khartoum, Khartoum, Sudan.
authors.forename: Ishag
authors.initials: I
authors.lastname: Adam
authors.affiliation: Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland.
authors.forename: Nikodem
authors.initials: N
authors.lastname: Grankowski
authors.affiliation: Department of Molecular Biology, Maria Curie-Skłodowska University, Akademicka 19, 20-033 Lublin, Poland. Electronic address: maro@hektor.umcs.lublin.pl.
authors.forename: Marek
authors.initials: M
authors.lastname: Tchórzewski
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010963:Plasmodium falciparum / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
chemical_list: D010750:Phosphoproteins; D015800:Protozoan Proteins; D011994:Recombinant Proteins; D012269:Ribosomal Proteins; C031937:phosphoprotein P2, ribosomal; C035690:ribosomal phosphoprotein P1; C054675:ribosomal protein P0
keywords: Malaria; Protein complexes; Protein–protein interactions; Ribosomal P proteins; Ribosomal stalk; Ribosomes