EMD-9572

Single-particle
3.5 Å
EMD-9572 Deposition: 11/10/2016
Map released: 01/02/2017
Last modified: 06/06/2018
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-9572

Structure of the large subunit of the chloro-ribosome

EMD-9572

Single-particle
3.5 Å
EMD-9572 Deposition: 11/10/2016
Map released: 01/02/2017
Last modified: 06/06/2018
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Spinach
Sample: Chloro-ribosome 50S
Fitted models: 5h1s (Avg. Q-score: 0.453)

Deposition Authors: Ahmed T, Yin Z, Bhushan S
Cryo-EM structure of the large subunit of the spinach chloroplast ribosome.
Ahmed T , Yin Z , Bhushan S
(2016) Sci Rep , 6 , 35793 - 35793
PUBMED: 27762343
DOI: doi:10.1038/srep35793
ISSN: 2045-2322
Abstract:
Protein synthesis in the chloroplast is mediated by the chloroplast ribosome (chloro-ribosome). Overall architecture of the chloro-ribosome is considerably similar to the Escherichia coli (E. coli) ribosome but certain differences are evident. The chloro-ribosome proteins are generally larger because of the presence of chloroplast-specific extensions in their N- and C-termini. The chloro-ribosome harbours six plastid-specific ribosomal proteins (PSRPs); four in the small subunit and two in the large subunit. Deletions and insertions occur throughout the rRNA sequence of the chloro-ribosome (except for the conserved peptidyl transferase center region) but the overall length of the rRNAs do not change significantly, compared to the E. coli. Although, recent advancements in cryo-electron microscopy (cryo-EM) have provided detailed high-resolution structures of ribosomes from many different sources, a high-resolution structure of the chloro-ribosome is still lacking. Here, we present a cryo-EM structure of the large subunit of the chloro-ribosome from spinach (Spinacia oleracea) at an average resolution of 3.5 Å. High-resolution map enabled us to localize and model chloro-ribosome proteins, chloroplast-specific protein extensions, two PSRPs (PSRP5 and 6) and three rRNA molecules present in the chloro-ribosome. Although comparable to E. coli, the polypeptide tunnel and the tunnel exit site show chloroplast-specific features.