Loading
PDBj
MenuPDBj@FacebookPDBj@TwitterPDBj@YouTubewwPDB FoundationwwPDB
RCSB PDBPDBeBMRBAdv. SearchSearch help

5MMM

Structure of the 70S chloroplast ribosome

This is a non-PDB format compatible entry.
Summary for 5MMM
Entry DOI10.2210/pdb5mmm/pdb
EMDB information3533
Descriptor50S ribosomal protein L31, 5S ribosomal RNA, 50S ribosomal protein L2, chloroplastic, ... (63 entities in total)
Functional Keywordschloroplast, translation, ribosome, cryo-em
Biological sourceSpinacia oleracea (Spinach)
More
Total number of polymer chains61
Total formula weight2618915.78
Authors
Bieri, P.,Leibundgut, M.,Saurer, M.,Boehringer, D.,Ban, N. (deposition date: 2016-12-11, release date: 2017-01-11, Last modification date: 2024-05-15)
Primary citationBieri, 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., 36:475-486, 2017
Cited by
PubMed Abstract: 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 Å 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.
PubMed: 28007896
DOI: 10.15252/embj.201695959
PDB entries with the same primary citation
Experimental method
ELECTRON MICROSCOPY (3.4 Å)
Structure validation

227111

PDB entries from 2024-11-06

PDB statisticsPDBj update infoContact PDBjnumon