Functional implications of ribosomal protein L2 in protein biosynthesis as shown by in vivo replacement studies

Abstract

The translational apparatus is a highly complex structure containing three to four RNA molecules and more than 50 different proteins. In recent years considerable evidence has accumulated to indicate that the RNA participates intensively in the catalysis of peptide-bond formation, whereas a direct involvement of the ribosomal proteins has yet to be demonstrated. Here we report the functional and structural conservation of a peptidyltransferase centre protein in all three phylogenetic domains. In i o replacement studies show that the Escherichia coli L2 protein can be replaced by its homologous proteins from human and

Symmetry at the active site of the ribosome: structural and functional implications

“…Signal transmission between the SymR and the small subunit can be mediated by several features, including the intersubunit bridges (Yusupov et al, 2001). These include helix H68 (bridge B7a) and helix H71 (bridge B3), the loop segments H69-71 and H67-71, protein L2 (bridge B7b), which was previously suggested to serve as a relay between the small subunit and the catalytic center in the large one (Uhlein et al, 1998), protein L14 (bridge B8), and A-and P-site tRNAs.…”

Defect in the Formation of 70S Ribosomes Caused by Lack of Ribosomal Protein L34 Can Be Suppressed by Magnesium

“…The individual functions of several ribosomal proteins have also been elucidated by biochemical and genetic analyses, including reconstitution and mutational analysis. For example, ribosomal protein L2 plays important roles in the assembly of the ribosomal subunits, binding of the tRNA to the A and P sites, peptidyltransferase activity, and formation of the peptide bond (9)(10)(11)(12)(13). However, in general, disruption of the genes that encode the ribosomal proteins has been avoided as a means of identifying protein function, because these genes, which are highly conserved in bacteria, have been considered essential for cell proliferation (14).…”

Ribosomal crystallography: a flexible nucleotide anchoring tRNA translocation, facilitates peptide‐bond formation, chirality discrimination and antibiotics synergism

“…The larger number of the intra-region interactions within the P-region [18], together with the interactions of the outer region of the P-region with the tail of protein L2 [18], could be responsible for this unbalanced stabilization. The necessity of protein L2 for the elongation of nascent polypeptides [24], contrary to the ability of protein-free 23S rRNA to form single peptide bonds [25], is consistent with the difference between these two stages of protein biosynthesis. Thus, single peptide bonds can be formed even by approximately placed reactants, as observed in the crystal structure of a complex of the large ribosomal subunit from Haloarcula marismortui, H50S [8,19], whereas the rotatory motion that leads to elongation can be performed only within a well-outlined pattern, hence necessitating an exact placement in a stable framework.…”