Ribosomal proteins. XXVI. The number of specific protein binding sites on 16 s and 23 s RNA of Escherichia coli

The identification of the RNA binding site for a 50 s ribosomal protein by a new technique

“…Complexes of the 23 S RNA with the purified protein L24 (the purification was carried out in the way described in [11 ] ) were prepared according to St6ffler et al [5], in the reconstitution buffer of Nomura and Erdmann [13]. The 23 S RNA was dissolved in this buffer at a concentration of 2 mg/ml.…”

“…coli ribosomes can bind individually and specifically to the ribosomal RNA's in vitro [1][2][3][4][5]. This presumably reflects fairly accurately the specific interactions between the RNA's and these proteins which exist in vivo.…”

Directed hydroxyl radical probing of 16S ribosomal RNA in ribosomes containing Fe(II) tethered to ribosomal protein S20

“…The binding of ribosomal protein S20 to 16S ribosomal RNA (rRNA), or fragments of 16S rRNA, has been investigated by a variety of methods (Sogin et al+, 1971;Daya-Grosjean et al+, 1974;Muto et al+, 1974;Zimmermann et al+, 1974Zimmermann et al+, , 1975Ungewickell et al+, 1975;Ehresmann et al+, 1977;Mackie & Zimmermann, 1978;Cormack & Mackie, 1991)+ Ribosomal protein S20 interacts with 16S rRNA stoichiometrically (Stöffler et al+, 1971;Muto & Zimmermann, 1978) and independently of other proteins, defining it as a primary binding protein (Mizushima & Nomura, 1970;Held et al+, 1974)+ These properties suggest that S20 plays a critical role in nucleating the assembly of the 30S subunit+ While the gene encoding S20 is not essential, strains lacking S20 have a significantly reduced growth rate (Dabbs, 1979;Götz et al+, 1989;Ryden-Aulin et al+, 1993)+ Defects in posttranscriptional modification of 16S rRNA, in vivo 30S subunit assembly, translational fidelity, and subunit association have all been identified in cells lacking S20 (Dabbs, 1979;Götz et al+, 1989;Ryden-Aulin et al+, 1993)+ Understanding the role of S20 in the ribosome is complicated not only by the multiple phenotypic effects observed in the deletion strain but also by discrepancies in the placement of S20 within the 30S subunit from different experimental approaches+ Neutron diffraction mapping has placed S20 in the head of the 30S subunit, near S3 and S10 (Capel et al+, 1987)+ In contrast, immunoelectron microscopy (IEM) has localized S20 near the bottom of the body of the 30S subunit, proximal to S17 and S15 (Schwedler et al+, 1993)+ Footprinting studies using RNA-directed probes specific to either the base or sugar moieties have identified nucleotides near positions 190, 250, 270, and 320, all elements of the 59 domain of 16S rRNA, as being some of the nucleotides protected by S20 (Stern et al+, 1988a;Powers & Noller, 1995)+ Ribosomal protein S17 also protects some of these same nucleotides from modification with base-specific chemical probes (Stern et al+, 1988a)+ This suggests that S17 and S20 are near one another in the 30S subunit+ Ribosomal protein S17 has been unambiguously positioned near the bottom of the body of the 30S subunit (Cap...…”

Active sites in Escherichia coli ribosomes

“…Therefore, it has been concluded that chloramphenicol binds to the A-site of the peptidyltransferase center. Partial reconstitution experiments have shown that protein L16, a 23 S RNA binding protein [68], is involved in chloramphenicol binding [67] . Affinity-labeling studies with monoiodoamphenicol, a chloramphenico1 analog, demonstrated that monoiodoamphenicol reacted exclusively with protein L16 [69].…”