Summary: Phycobilisome protein
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This is the Wikipedia entry entitled "Phycobilisome". More...
Phycobilisome Edit Wikipedia article
A phycobilisome is a light harvesting protein present in cyanobacteria and red algae. Flourescent pigments, which are linked to the peptide chain absorb green light in the region of 470-650nm. Other pigments which are present in the the bacterial photosynthetic reaction centres, like bacteriochlorophyll and bacteriopheophytin do not absorb light in these regions. The flourescent pigments which are present in the phycobilisome, such as phycocyanobilin and phycoerythrobilin re-emit the green light in regions which the other photosynthetic pigments can absorb.
The geometrical arrangement of a phycobilisome is very elegant and results in 95% effiency of energy transfer. There is a central core of AP and APB subunits which sits above the photosynthetic reaction centre. There are PC and PE subunits which radiate out from this centre like thin tubes. This increases the surface area of the absorbing section and helps focus and concentrate light energy down into the reaction centre.
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This is the Wikipedia entry entitled "Phycocyanin". More...
Phycocyanin Edit Wikipedia article
Phycocyanin is a pigment that is blue and is readily found in blue-green algae.
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This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
Phycobilisome protein Provide feedback
No Pfam abstract.
External database links
HOMSTRAD: | phc |
SCOP: | 1cpc |
This tab holds annotation information from the InterPro database.
InterPro entry IPR012128
Cyanobacteria and red algae harvest light through water-soluble complexes, called phycobilisomes, which are attached to the outer face of the thylakoid membrane [ PUBMED:15238265 ]. These complexes are capable of transferring the absorbed energy to the photosynthetic reaction centre with greater than 95% efficiency. Phycobilisomes contain various photosynthetic light harvesting proteins known as biliproteins, and linker proteins which help assemble the structure. The two main structural elements of the complex are a core located near the photosynthetic reaction centre, and rods attached to this core. Allophycocyanin is the major component of the core, while the rods contain phycocyanins, phycoerythrins and linker proteins. The rod biliproteins harvest photons, with the excitation energy being passed through the rods into the allophycocyanin in the core. Other core biliproteins subsequently pass this energy to chlorophyll within the thylakoid membrane.
This entry represents the alpha and beta subunits found in biliproteins from cyanobacteria and red algae. Structural studies indicate that the basic structural unit of most biliproteins is a heterodimer composed of these alpha and beta subunits [ PUBMED:10388620 , PUBMED:11134927 , PUBMED:11463658 , PUBMED:7783202 ]. The full protein is a ring-like trimer assembly of these heterodimers. Each subunit of the heterodimer has eight helices and binds chromophores through thioester bonds formed at particular cysteine residues. These chromophores, also known as bilins, are open-chain tetrapyrroles whose number and type vary with the particular biliprotein eg R-phyocerythrin binds five phycoerythrobilins per heterodimer, while allophycocyanin binds two phycocyanobilins per heterodimer.
Gene Ontology
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
Cellular component | phycobilisome (GO:0030089) |
Biological process | photosynthesis (GO:0015979) |
Domain organisation
Below is a listing of the unique domain organisations or architectures in which this domain is found. More...
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Pfam Clan
This family is a member of clan Globin (CL0090), which has the following description:
The globin fold is an evolutionary conserved six helical fold that is found in bacteria and eukaryotes.
The clan contains the following 8 members:
Bac_globin Globin HisK-N-like HisK_N Phycobilisome Protoglobin Rsbr_N RsbRD_NAlignments
We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...
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We make a range of alignments for each Pfam-A family. You can see a description of each above. You can view these alignments in various ways but please note that some types of alignment are never generated while others may not be available for all families, most commonly because the alignments are too large to handle.
Seed (132) |
Full (1889) |
Representative proteomes | UniProt (15005) |
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RP15 (145) |
RP35 (1001) |
RP55 (1946) |
RP75 (3443) |
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PP/heatmap | 1 |
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key:
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Seed (132) |
Full (1889) |
Representative proteomes | UniProt (15005) |
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RP15 (145) |
RP35 (1001) |
RP55 (1946) |
RP75 (3443) |
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Raw Stockholm | |||||||
Gzipped |
You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.
HMM logo
HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...
Trees
This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.
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Curation and family details
This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.
Curation
Seed source: | Pfam-B_10 (release 1.0) |
Previous IDs: | none |
Type: | Domain |
Sequence Ontology: | SO:0000417 |
Author: |
Finn RD |
Number in seed: | 132 |
Number in full: | 1889 |
Average length of the domain: | 142.3 aa |
Average identity of full alignment: | 28 % |
Average coverage of the sequence by the domain: | 64.12 % |
HMM information
HMM build commands: |
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
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Model details: |
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Model length: | 155 | ||||||||||||
Family (HMM) version: | 22 | ||||||||||||
Download: | download the raw HMM for this family |
Species distribution
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Structures
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Phycobilisome domain has been found. There are 1146 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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AlphaFold Structure Predictions
The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.