[English] 日本語
Yorodumi
- EMDB-56561: Structure of the Chlamydomonas reinhardtii chlororibosome with P-... -

+
Open data


ID or keywords:

Loading...

-
Basic information

Entry
Database: EMDB / ID: EMD-56561
TitleStructure of the Chlamydomonas reinhardtii chlororibosome with P-site tRNA - consensus map
Map data
Sample
  • Complex: Chloroplast ribosome
Keywordschloroplast / ribosome / translation / chlororibosome
Biological speciesChlamydomonas reinhardtii (plant)
Methodsingle particle reconstruction / cryo EM / Resolution: 2.84 Å
AuthorsWaltz F / Engel BD
Funding support Switzerland, 2 items
OrganizationGrant numberCountry
Swiss National Science Foundation216094 Switzerland
Swiss State Secretariat for Education, Research and InnovationM822.00045 Switzerland
CitationJournal: bioRxiv / Year: 2026
Title: Chloroplast-encoded small subunit extensions reshape the Chlamydomonas chlororibosome.
Authors: Florent Waltz / Philippe A Lehner / Philippe Van der Stappen / Lukas Kater / Stefan Pfeffer / Benjamin D Engel /
Abstract: Chloroplast ribosomes (chlororibosomes) synthesize the core protein components of the photosynthetic apparatus, yet their structural diversity outside flowering plants remains largely unexplored. ...Chloroplast ribosomes (chlororibosomes) synthesize the core protein components of the photosynthetic apparatus, yet their structural diversity outside flowering plants remains largely unexplored. Here, we combine in situ cryo-electron tomography (cryo-ET) with single-particle cryo-electron microscopy (cryo-EM) to determine the structure of the chlororibosome from the unicellular green alga . Subtomogram averaging of chlororibosomes in their native environment, resolved to ~5 Å resolution and in distinct translational states, reveals particles both free in the stroma and loosely tethered to thylakoid membranes. These reconstructions uncover an additional "arm" domain on the small subunit. High-resolution single-particle reconstruction of isolated chlororibosomes to ~2.5 Å, in states bound either to the inhibitory translation factor pY or to a nascent chain-linked P-site tRNA, reveals that this domain is built primarily from extensive chloroplast-encoded insertions and extensions of conserved small subunit proteins, supported by chlororibosome-specific ribosomal proteins. The arm domain is located around the mRNA entry and exit channels, suggesting a role in stabilizing the mRNA trajectory through the small subunit and organizing chloroplast polysomes. Together, these data reveal unexpected structural variation of algal chlororibosomes and suggest that chloroplast translation has diversified substantially even among relatively closely related photosynthetic lineages.
History
DepositionFeb 4, 2026-
Header (metadata) releaseFeb 18, 2026-
Map releaseFeb 18, 2026-
UpdateMar 11, 2026-
Current statusMar 11, 2026Processing site: PDBe / Status: Released

-
Structure visualization

Supplemental images

emd_56561.png

Downloads & links

-
Map

FileDownload / File: emd_56561.map.gz / Format: CCP4 / Size: 512 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
Projections & slices

Image control

Size
Brightness
Contrast
Others
AxesZ (Sec.)Y (Row.)X (Col.)
1.06 Å/pix.
x 512 pix.
= 544.307 Å		1.06 Å/pix.
x 512 pix.
= 544.307 Å		1.06 Å/pix.
x 512 pix.
= 544.307 Å

Surface

Projections

Slices (1/3)

Slices (1/2)

Slices (2/3)

Images are generated by Spider.

Voxel sizeX=Y=Z: 1.0631 Å
Density

Histogram

Histogram (log scale)
Contour LevelBy AUTHOR: 0.0909
Minimum - Maximum-0.31945866 - 0.7149483
Average (Standard dev.)-0.00033151277 (±0.022020787)
SymmetrySpace group: 1
Details

EMDB XML:

Map geometry
Axis orderXYZ
Origin000
Dimensions512512512
Spacing512512512
CellA=B=C: 544.3072 Å
α=β=γ: 90.0 °

-
Supplemental data

-
Mask #1

Fileemd_56561_msk_1.map
Projections & Slices
AxesZYX

Projections

Slices (1/2)
Density Histograms

Histogram

Histogram (log scale)

-
Half map: #1

Fileemd_56561_half_map_1.map
Projections & Slices
AxesZYX

Projections

Slices (1/2)
Density Histograms

Histogram

Histogram (log scale)

-
Half map: #2

Fileemd_56561_half_map_2.map
Projections & Slices
AxesZYX

Projections

Slices (1/2)
Density Histograms

Histogram

Histogram (log scale)

-
Sample components

-
Entire : Chloroplast ribosome

EntireName: Chloroplast ribosome
Components
  • Complex: Chloroplast ribosome

-
Supramolecule #1: Chloroplast ribosome

SupramoleculeName: Chloroplast ribosome / type: complex / ID: 1 / Parent: 0
Source (natural)Organism: Chlamydomonas reinhardtii (plant) / Strain: mat3-4

-
Experimental details

-
Structure determination

Methodcryo EM
Processingsingle particle reconstruction
Aggregation stateparticle

-
Sample preparation

Concentration2.5 mg/mL
BufferpH: 7.5
GridModel: Quantifoil R2/1 / Material: COPPER / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 20 sec.
VitrificationCryogen name: ETHANE / Chamber humidity: 100 % / Instrument: FEI VITROBOT MARK IV

-
Electron microscopy

MicroscopeTFS KRIOS
Image recordingFilm or detector model: TFS FALCON 4i (4k x 4k) / Average electron dose: 40.0 e/Å2
Electron beamAcceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN
Electron opticsIllumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.0 µm / Nominal defocus min: 0.8 µm / Nominal magnification: 75000
Experimental equipment
Model: Titan Krios / Image courtesy: FEI Company

+
Image processing

CTF correctionSoftware - Name: cryoSPARC (ver. 4.7) / Type: PHASE FLIPPING AND AMPLITUDE CORRECTION
Startup modelType of model: NONE
Final reconstructionAlgorithm: BACK PROJECTION / Resolution.type: BY AUTHOR / Resolution: 2.84 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: cryoSPARC (ver. 4.7) / Number images used: 49141
Initial angle assignmentType: MAXIMUM LIKELIHOOD / Software - Name: cryoSPARC (ver. 4.7)
Final angle assignmentType: MAXIMUM LIKELIHOOD / Software - Name: cryoSPARC (ver. 4.7)
Final 3D classificationSoftware - Name: cryoSPARC (ver. 4.7)
FSC plot (resolution estimation)

+
About Yorodumi

-
News

-
Feb 9, 2022. New format data for meta-information of EMDB entries

New format data for meta-information of EMDB entries

  • Version 3 of the EMDB header file is now the official format.
  • The previous official version 1.9 will be removed from the archive.

Related info.:EMDB header

External links:wwPDB to switch to version 3 of the EMDB data model

-
Aug 12, 2020. Covid-19 info

Covid-19 info

URL: https://pdbj.org/emnavi/covid19.php

New page: Covid-19 featured information page in EM Navigator.

Related info.:Covid-19 info / Mar 5, 2020. Novel coronavirus structure data

+
Mar 5, 2020. Novel coronavirus structure data

Novel coronavirus structure data

Related info.:Yorodumi Speices / Aug 12, 2020. Covid-19 info

External links:COVID-19 featured content - PDBj / Molecule of the Month (242)：Coronavirus Proteases

+
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)

EMDB accession codes are about to change! (news from PDBe EMDB page)

  • The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
  • The EM Navigator/Yorodumi systems omit the EMD- prefix.

Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator

External links:EMDB Accession Codes are Changing Soon! / Contact to PDBj

+
Jul 12, 2017. Major update of PDB

Major update of PDB

  • wwPDB released updated PDB data conforming to the new PDBx/mmCIF dictionary.
  • This is a major update changing the version number from 4 to 5, and with Remediation, in which all the entries are updated.
  • In this update, many items about electron microscopy experimental information are reorganized (e.g. em_software).
  • Now, EM Navigator and Yorodumi are based on the updated data.

External links:wwPDB Remediation / Enriched Model Files Conforming to OneDep Data Standards Now Available in the PDB FTP Archive

-
Yorodumi

Thousand views of thousand structures

  • Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
  • This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
  • The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.

Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi

Read more