An eIF-4A-like protein is a suppressor of an Escherichia coli mutant defective in 50S ribosomal subunit assembly

ABSTRACT The aminoglycosides paromomycin and neomycin were examined in Escherichia coli cells for an inhibitory effect on 30S ribosomal subunit assembly. Both compounds inhibited the growth rate, viable cell number, and protein synthesis rate with similar 50% inhibitory concentrations. Each drug also showed a concentration-dependent inhibition of 30S subunit formation. The inhibitory effect on 30S particle formation was approximately equivalent to the inhibitory effect on translation for these antibiotics.

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The Loop 2 Region of Ribosomal Protein uS5 Influences Spectinomycin Sensitivity, Translational Fidelity, and Ribosome Biogenesis

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01186-16 ◽

2016 ◽

Vol 61 (2) ◽

Cited By ~ 3

Author(s):

Divya Kamath ◽

Steven T. Gregory ◽

Michael O'Connor

Keyword(s):

Escherichia Coli ◽

Ribosomal Protein ◽

Recent Work ◽

Ribosome Biogenesis ◽

Ribosomal Subunit ◽

Rrna Processing ◽

Translational Fidelity ◽

Subunit Assembly ◽

Essential Component ◽

Loop 2

ABSTRACT Ribosomal protein uS5 is an essential component of the small ribosomal subunit that is involved in subunit assembly, maintenance of translational fidelity, and the ribosome's response to the antibiotic spectinomycin. While many of the characterized uS5 mutations that affect decoding map to its interface with uS4, more recent work has shown that residues distant from the uS4-uS5 interface can also affect the decoding process. We targeted one such interface-remote area, the loop 2 region (residues 20 to 31), for mutagenesis in Escherichia. coli and generated 21 unique mutants. A majority of the loop 2 alterations confer resistance to spectinomycin and affect the fidelity of translation. However, only a minority show altered rRNA processing or ribosome biogenesis defects.

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Single methylation of 23S rRNA triggers late steps of 50S ribosomal subunit assembly

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1506749112 ◽

2015 ◽

Vol 112 (34) ◽

pp. E4707-E4716 ◽

Cited By ~ 26

Author(s):

Taiga Arai ◽

Kensuke Ishiguro ◽

Satoshi Kimura ◽

Yuriko Sakaguchi ◽

Takeo Suzuki ◽

...

Keyword(s):

Escherichia Coli ◽

Ribosome Biogenesis ◽

Slow Growth ◽

Genetic Interaction ◽

Ribosomal Subunit ◽

23S Rrna ◽

Subunit Assembly ◽

Interdomain Interactions ◽

Multiple Assembly

Ribosome biogenesis requires multiple assembly factors. In Escherichia coli, deletion of RlmE, the methyltransferase responsible for the 2′-O-methyluridine modification at position 2552 (Um2552) in helix 92 of the 23S rRNA, results in slow growth and accumulation of the 45S particle. We demonstrate that the 45S particle that accumulates in ΔrlmE is a genuine precursor that can be assembled into the 50S subunit. Indeed, 50S formation from the 45S precursor could be promoted by RlmE-mediated Um2552 formation in vitro. Ribosomal protein L36 (encoded by rpmJ) was completely absent from the 45S precursor in ΔrlmE, and we observed a strong genetic interaction between rlmE and rpmJ. Structural probing of 23S rRNA and high-salt stripping of 45S components revealed that RlmE-mediated methylation promotes interdomain interactions via the association between helices 92 and 71, stabilized by the single 2′-O-methylation of Um2552, in concert with the incorporation of L36, triggering late steps of 50S subunit assembly.

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