Crystal structure of the E. coli ribosome bound to dalfopristin and quinupristin.Crystal structure of the E. coli ribosome bound to dalfopristin and quinupristin.

Structural highlights

4u26 is a 20 chain structure with sequence from Escherichia coli K-12 and Escherichia coli str. K-12 substr. MDS42. This structure supersedes the now removed PDB entries 4tp8, 4tp9, 4tpa and 4tpb. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.8Å
Ligands:, , , , , , , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RS5_ECOLI With S4 and S12 plays an important role in translational accuracy. Many suppressors of streptomycin-dependent mutants of protein S12 are found in this protein, some but not all of which decrease translational accuracy (ram, ribosomal ambiguity mutations).[1] Located at the back of the 30S subunit body where it stabilizes the conformation of the head with respect to the body.[2] The physical location of this protein suggests it may also play a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.[3]

Publication Abstract from PubMed

Streptogramin antibiotics are divided into type A and B streptogramins, which in combination can act synergistically. We compared the molecular interactions of the streptogramin combinations Synercid (type A: dalfopristin, type B: quinupristin) and NXL 103 (type A: flopristin, type B: linopristin) with the Escherichia coli 70S ribosome by x-ray crystallography. We further analyzed the activity of the streptogramin components individually and in combination. Streptogramin A and B components in Synercid and NXL 103 exhibit synergistic antimicrobial activity against certain pathogenic bacteria. However, in transcription-coupled translation assays, only combinations that include dalfopristin, the streptogramin A component of Synercid, show synergy. Notably, the diethylaminoethylsulfonyl group in dalfopristin reduces its activity, but is the basis for synergy in transcription-coupled translation assays before its rapid hydrolysis from the depsipeptide core. Replacement of the diethylaminoethylsulfonyl group in dalfopristin by a non-hydrolyzable group may therefore be beneficial for synergy. The absence of general streptogramin synergy in transcription-coupled translation assays suggests that synergistic antimicrobial activity of streptogramins can occur independently of streptogramin effects on translation.

Synergy of streptogramin antibiotics occurs independently of their effects on translation.,Noeske J, Huang J, Olivier NB, Giacobbe RA, Zambrowski M, Cate JH Antimicrob Agents Chemother. 2014 Jun 23. pii: AAC.03389-14. PMID:24957822[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
  2. Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
  3. Takyar S, Hickerson RP, Noller HF. mRNA helicase activity of the ribosome. Cell. 2005 Jan 14;120(1):49-58. PMID:15652481 doi:10.1016/j.cell.2004.11.042
  4. Noeske J, Huang J, Olivier NB, Giacobbe RA, Zambrowski M, Cate JH. Synergy of streptogramin antibiotics occurs independently of their effects on translation. Antimicrob Agents Chemother. 2014 Jun 23. pii: AAC.03389-14. PMID:24957822 doi:http://dx.doi.org/10.1128/AAC.03389-14

4u26, resolution 2.80Å

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