5mmi

From Proteopedia

Jump to: navigation, search

Structure of the large subunit of the chloroplast ribosome

Structural highlights

5mmi is a 10 chain structure with sequence from Spinacia oleracea. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:Electron Microscopy, Resolution 3.25Å
Experimental data:Check to display Experimental Data
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

RK33_SPIOL

Publication Abstract from PubMed

Chloroplasts are cellular organelles of plants and algae that are responsible for energy conversion and carbon fixation by the photosynthetic reaction. As a consequence of their endosymbiotic origin, they still contain their own genome and the machinery for protein biosynthesis. Here, we present the atomic structure of the chloroplast 70S ribosome prepared from spinach leaves and resolved by cryo-EM at 3.4 A resolution. The complete structure reveals the features of the 4.5S rRNA, which probably evolved by the fragmentation of the 23S rRNA, and all five plastid-specific ribosomal proteins. These proteins, required for proper assembly and function of the chloroplast translation machinery, bind and stabilize rRNA including regions that only exist in the chloroplast ribosome. Furthermore, the structure reveals plastid-specific extensions of ribosomal proteins that extensively remodel the mRNA entry and exit site on the small subunit as well as the polypeptide tunnel exit and the putative binding site of the signal recognition particle on the large subunit. The translation factor pY, involved in light- and temperature-dependent control of protein synthesis, is bound to the mRNA channel of the small subunit and interacts with 16S rRNA nucleotides at the A-site and P-site, where it protects the decoding centre and inhibits translation by preventing tRNA binding. The small subunit is locked by pY in a non-rotated state, in which the intersubunit bridges to the large subunit are stabilized.

The complete structure of the chloroplast 70S ribosome in complex with translation factor pY.,Bieri P, Leibundgut M, Saurer M, Boehringer D, Ban N EMBO J. 2016 Dec 22. pii: e201695959. doi: 10.15252/embj.201695959. PMID:28007896[1]

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

Loading citation details..
Citations
reviews cite this structure
No citations found

See Also

References

  1. Bieri P, Leibundgut M, Saurer M, Boehringer D, Ban N. The complete structure of the chloroplast 70S ribosome in complex with translation factor pY. EMBO J. 2016 Dec 22. pii: e201695959. doi: 10.15252/embj.201695959. PMID:28007896 doi:http://dx.doi.org/10.15252/embj.201695959

Contents


5mmi, resolution 3.25Å

Proteopedia Page Contributors and Editors (what is this?)

OCA

Personal tools