7LIX

CaRSP1 and scaffolded phycoerythrin beta subunits from the phycobilisome of Porphyridium purpureum


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.0 of the entry. See complete history


Literature

Scaffolding proteins guide the evolution of algal light harvesting antennas.

Rathbone, H.W.Michie, K.A.Landsberg, M.J.Green, B.R.Curmi, P.M.G.

(2021) Nat Commun 12: 1890-1890

  • DOI: https://doi.org/10.1038/s41467-021-22128-w
  • Primary Citation of Related Structures:  
    7LIX, 7LIY, 7LIZ, 7LJ0

  • PubMed Abstract: 

    Photosynthetic organisms have developed diverse antennas composed of chromophorylated proteins to increase photon capture. Cryptophyte algae acquired their photosynthetic organelles (plastids) from a red alga by secondary endosymbiosis. Cryptophytes lost the primary red algal antenna, the red algal phycobilisome, replacing it with a unique antenna composed of αβ protomers, where the β subunit originates from the red algal phycobilisome. The origin of the cryptophyte antenna, particularly the unique α subunit, is unknown. Here we show that the cryptophyte antenna evolved from a complex between a red algal scaffolding protein and phycoerythrin β. Published cryo-EM maps for two red algal phycobilisomes contain clusters of unmodelled density homologous to the cryptophyte-αβ protomer. We modelled these densities, identifying a new family of scaffolding proteins related to red algal phycobilisome linker proteins that possess multiple copies of a cryptophyte-α-like domain. These domains bind to, and stabilise, a conserved hydrophobic surface on phycoerythrin β, which is the same binding site for its primary partner in the red algal phycobilisome, phycoerythrin α. We propose that after endosymbiosis these scaffolding proteins outcompeted the primary binding partner of phycoerythrin β, resulting in the demise of the red algal phycobilisome and emergence of the cryptophyte antenna.


  • Organizational Affiliation

    School of Physics, University of New South Wales, Sydney, NSW, 2052, Australia.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
CaRSP1288Porphyridium purpureumMutation(s): 0 
UniProt
Find proteins for A0A5J4YJY8 (Porphyridium purpureum)
Explore A0A5J4YJY8 
Go to UniProtKB:  A0A5J4YJY8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A5J4YJY8
Sequence Annotations
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
B-phycoerythrin beta chain
B, C, D
177Porphyridium purpureumMutation(s): 0 
UniProt
Find proteins for P11393 (Porphyridium purpureum)
Explore P11393 
Go to UniProtKB:  P11393
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP11393
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.80 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX1.18
MODEL REFINEMENTCoot0.8.9.2
MODEL REFINEMENTISOLDE1.1

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Australian Research Council (ARC)AustraliaDP180103964
Australian Research Council (ARC)AustraliaLIEF190100165
Department of Defense (DOD, United States)United StatesFA2386-17-1-4101

Revision History  (Full details and data files)

  • Version 1.0: 2021-04-07
    Type: Initial release