Please note: this site relies heavily on the use of javascript. Without a javascript-enabled browser, this site will not function correctly. Please enable javascript and reload the page, or switch to a different browser.
17  structures 985  species 5  interactions 1035  sequences 5  architectures

Family: PsbL (PF02419)

Summary: PsbL protein

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.

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.

PsbL protein Provide feedback

This family consists of the photosystem II reaction centre protein PsbJ from plants and Cyanobacteria. The function of this small protein is unknown. Interestingly the mRNA for this protein requires a post-transcriptional modification of an ACG triplet to form an AUG initiator codon [1,2].

Literature references

  1. Kuntz M, Camara B, Weil JH, Schantz R; , Plant Mol Biol 1992;20:1185-1188.: The psbL gene from bell pepper (Capsicum annuum): plastid RNA editing also occurs in non-photosynthetic chromoplasts. PUBMED:1463853 EPMC:1463853

  2. Kudla J, Igloi GL, Metzlaff M, Hagemann R, Kossel H; , EMBO J 1992;11:1099-1103.: RNA editing in tobacco chloroplasts leads to the formation of a translatable psbL mRNA by a C to U substitution within the initiation codon. PUBMED:1547774 EPMC:1547774


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR003372

Oxygenic photosynthesis uses two multi-subunit photosystems (I and II) located in the cell membranes of cyanobacteria and in the thylakoid membranes of chloroplasts in plants and algae. Photosystem II (PSII) has a P680 reaction centre containing chlorophyll 'a' that uses light energy to carry out the oxidation (splitting) of water molecules, and to produce ATP via a proton pump. Photosystem I (PSI) has a P700 reaction centre containing chlorophyll that takes the electron and associated hydrogen donated from PSII to reduce NADP+ to NADPH. Both ATP and NADPH are subsequently used in the light-independent reactions to convert carbon dioxide to glucose using the hydrogen atom extracted from water by PSII, releasing oxygen as a by-product.

PSII is a multisubunit protein-pigment complex containing polypeptides both intrinsic and extrinsic to the photosynthetic membrane [PUBMED:12518057, PUBMED:15100025]. Within the core of the complex, the chlorophyll and beta-carotene pigments are mainly bound to the antenna proteins CP43 (PsbC) and CP47 (PsbB), which pass the excitation energy on to the reaction centre proteins D1 (Qb, PsbA) and D2 (Qa, PsbD) that bind all the redox-active cofactors involved in the energy conversion process. The PSII oxygen-evolving complex (OEC) oxidises water to provide protons for use by PSI, and consists of OEE1 (PsbO), OEE2 (PsbP) and OEE3 (PsbQ). The remaining subunits in PSII are of low molecular weight (less than 10 kDa), and are involved in PSII assembly, stabilisation, dimerisation, and photo-protection [PUBMED:14871485].

This family represents the low molecular weight transmembrane protein PsbL found in PSII. PsbL is located in a gene cluster with PsbE, PsbF and PsbJ (PsbEFJL). Both PsbL and PsbJ (INTERPRO) are essential for proper assembly of the OEC. Mutations in PsbL prevent the formation of both PSII core dimers and PSII-light harvesting complex [PUBMED:14686923]. In addition, both PsbL and PsbJ are involved in the unidirectional flow of electrons, where PsbJ regulates the forward electron flow from D2 (Qa) to the plastoquinone pool, and PsbL prevents the reduction of PSII by back electron flow from plastoquinol protecting PSII from photo-inactivation [PUBMED:14979726].

Gene Ontology

The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

Loading domain graphics...

Alignments

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 using the family HMM. We also generate alignments using four representative proteomes (RP) sets, the NCBI sequence database, and our metagenomics sequence database. More...

View options

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
(14)
Full
(1035)
Representative proteomes NCBI
(215)
Meta
(89)
RP15
(14)
RP35
(32)
RP55
(41)
RP75
(49)
Jalview View  View  View  View  View  View  View  View 
HTML View  View  View  View  View  View     
PP/heatmap 1 View  View  View  View  View     
Pfam viewer View  View             

1Cannot generate PP/Heatmap alignments for seeds; no PP data available

Key: ✓ available, x not generated, not available.

Format an alignment

  Seed
(14)
Full
(1035)
Representative proteomes NCBI
(215)
Meta
(89)
RP15
(14)
RP35
(32)
RP55
(41)
RP75
(49)
Alignment:
Format:
Order:
Sequence:
Gaps:
Download/view:

Download options

We make all of our alignments available in Stockholm format. You can download them here as raw, plain text files or as gzip-compressed files.

  Seed
(14)
Full
(1035)
Representative proteomes NCBI
(215)
Meta
(89)
RP15
(14)
RP35
(32)
RP55
(41)
RP75
(49)
Raw Stockholm Download   Download   Download   Download   Download   Download   Download   Download  
Gzipped Download   Download   Download   Download   Download   Download   Download   Download  

You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

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.

Note: You can also download the data file for the tree.

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 View help on the curation process

Seed source: Pfam-B_1884 (release 5.4)
Previous IDs: none
Type: Family
Author: Bateman A
Number in seed: 14
Number in full: 1035
Average length of the domain: 36.70 aa
Average identity of full alignment: 90 %
Average coverage of the sequence by the domain: 86.43 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 19.7 19.7
Trusted cut-off 20.4 20.4
Noise cut-off 18.6 17.4
Model length: 37
Family (HMM) version: 12
Download: download the raw HMM for this family

Species distribution

Sunburst controls

Show

This visualisation provides a simple graphical representation of the distribution of this family across species. You can find the original interactive tree in the adjacent tab. More...

Loading sunburst data...

Tree controls

Hide

The tree shows the occurrence of this domain across different species. More...

Loading...

Please note: for large trees this can take some time. While the tree is loading, you can safely switch away from this tab but if you browse away from the family page entirely, the tree will not be loaded.

Interactions

There are 5 interactions for this family. More...

PSII PsbM Photo_RC PsbT PsbL

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 PsbL domain has been found. There are 17 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 seqence.

Loading structure mapping...