Posts Tagged ‘pfam’

A new Pfam-B is released

June 30, 2020

In addition to our HMM-based Pfam entries (Pfam-A), we used to make a set of automatically generated, non-HMM based entries called Pfam-B. The Pfam-B entries were derived from clusters generated by applying the ADDA algorithm to an all-against-all BLAST search of UniRef-40, and removing any regions covered by Pfam-A. The overhead of producing Pfam-B in this way became too great, and as of Pfam 28.0, we stopped making Pfam-B entries (see [1] for a longer discussion on why we stopped producing Pfam-B). Erik Sonnhammer has devised an alternative method of making Pfam-B using the MMSeqs2 software [2], and an overview of the process is given below (more details will follow in the next Pfam paper).

We have already begun to use the new version of Pfam-B to generate new families, and 11 of these are in Pfam 33.1. For example, the TUTase family (PF19088) was built using Pfam-B as the source. We expect that Pfam-B will be a very useful source of additional families in the coming years.

How the new Pfam-B was created

UniProtKB sequences not covered by Pfam-A were clustered using MMSeqs2 and multiple sequence alignments of each cluster were generated with FAMSA [3]. This resulted in 136730 Pfam-B families that on average contain 99 sequences (max 40912) and are 310 positions wide (max 29216).

How to access the new Pfam-B

The Pfam-B alignments are released as a tar archive on the Pfam FTP site [Pfam-B.tgz]. We do not plan to integrate them into the Pfam website, but we will generate them for each future Pfam release.

Posted by Erik Sonnhammer and the Pfam team

References

1. Finn et al. (2015) The Pfam protein families database: towards a more sustainable future.

2. Hauser et al. (2016) MMseqs software suite for fast and deep clustering and searching of large protein sequence sets

3. Deorowicz et al. (2016) FAMSA: Fast and accurate multiple sequence alignment of huge protein families

Pfam 33.1 is released

June 11, 2020

We are pleased to announce the release of Pfam 33.1! Some of you may have noticed that we never released Pfam 33.0 – we had initially planned to do so in March 2020, but due to the global pandemic, we redirected our efforts to updating the Pfam SARS-CoV-2 models instead (see previous blog posts Pfam SARS-CoV-2 special update and Pfam SARS-CoV-2 special update (part 2)). We have added these updated models to the Pfam 33.0 release, along with a few other families that we had built since the data for Pfam 33.0 were frozen, to create Pfam 33.1.

Pfam 33.1 contains a total of 18259 families and 635 clans. Since the last release, we have built 355 new families and killed 25 families. We regularly receive feedback from users about families or domains that are missing in Pfam, and typically add many user submitted families at each release. We include the submitters name and ORCID identifier as an author of such Pfam entries. This helps people to get credit for community activities that improve molecular biology databases such as Pfam.

One such user submission was from Heli Mönttinen (University of Helsinki) who submitted a large scale clustering of virus families. Based on this clustering we added 88 new families to Pfam. 

We have also added 8 new clans since the last Pfam release. One of the new clans is the TSP1 superfamily (CL0692). Previously a single family (PF00090) attempted to identify all known TSP1 domains.  Based on structural work by Marko Hyvönen (University of Cambridge) and colleagues we have added an additional three families (PF19028PF19030 and PF19035) to Pfam. These new families have both improved the coverage of the TSP1 domain, and better modelled the variations in disulphide binding across the structure space.           

Figure 1. Organisation of the TSP1 clan in Pfam shown as a sequence similarity network. Image taken from Xu et al.

Finally, we are very happy to welcome Sara and Lowri who are working as curators for both the Pfam and InterPro resources and are already making great contributions to the resources.

Posted by Jaina and Alex

Pfam SARS-CoV-2 special update (part 2)

April 6, 2020

This post presents an update to last week’s post. Since the initial release of the 40 Pfam profile HMMs that match SARS-CoV-2, we have now produced a set of flatfiles that are more typical of a Pfam release.  These files make our updated annotations that describe the entries available for download, prior to being released via the Pfam website. Moreover, you can now use the multiple sequence alignments to investigate the conserved positions across different coronavirus proteins. Figure 1 shows the alignment of the SARS-CoV-2 receptor binding domain (PF09408 N.B. the Pfam website still shows the old alignment).

pf09408-spike

Figure 1 – Excerpt of the Betacoronavirus spike glycoprotein S1, receptor binding domain alignment (Pfam accession PF09408), rendered using Jalview. The SARS-CoV-2 sequence is the last sequence in the alignment.

Finally, we have made some very minor changes to the family descriptions and one name change from the last release.  You can now access all the updated files here:

ftp://ftp.ebi.ac.uk/pub/databases/Pfam/releases/Pfam_SARS-CoV-2_2.0/

In this directory you can find the updated seed (Pfam-A.SARS-CoV-2.seed) and full alignments (Pfam-A.SARS-CoV-2.full) in Stockholm format based on the Pfamseq database, which contains sequences of the UniProt Reference Proteomes.  We provide a file with matches to UniProtKB 2019_08 (Pfam-A.SARS-CoV-2.full.uniprot). We also provide a set of alignments for each of the families which include matches to the SARS-CoV-2 sequences which are not as yet present in the Pfamseq database. These alignments can be found in aligned fasta format here or as a tar gzipped library here.

Posted by The Pfam team

Pfam SARS-CoV-2 special update

April 2, 2020

The SARS-CoV-2 pandemic has mobilised a worldwide research effort to understand the pathogen itself and the mechanism of COVID-19 disease, as well as to identify treatment options. Although Pfam already provided useful annotation for SARS-CoV-2, we decided to update our models and annotations for this virus in an effort to help the research community. This post explains what was done and how we are making the data available as quickly as possible.

What have we done?

We assessed all the protein sequences provided by UniProt via its new COVID-19 portal (https://covid-19.uniprot.org/), identified those which lacked an existing Pfam model, and set about building models as required. In some cases we built families based on recently solved structures of SARS-CoV-2 proteins. For example, we built three new families representing the three structural domains of the NSP15 protein (Figure 1) based on the structure by Youngchang Kim and colleagues (http://europepmc.org/article/PPR/PPR115432). In other cases, such as Pfam’s RNA dependent RNA polymerase family (PF00680), we took our existing family and extended its taxonomic range to ensure it included the new SARS-CoV-2 sequences.

Figure 1. The structure of NSP15 (PDB:6VWW) from Kim et al. shows the three new Pfam domains. (1) CoV_NSP15_N (PF19219) Coronavirus replicase NSP15, N-terminal oligomerisation domain in red, (2) CoV_NSP15_M (PF19216) Coronavirus replicase NSP15, middle domain in blue and (3) CoV_NSP15_C (PF19215) Coronavirus replicase NSP15, uridylate-specific endoribonuclease in green.

We have also stratified our ID nomenclature and descriptions of the families to ensure they are both correct and consistent. The majority of the family identifiers now begin with either CoV, for coronavirus specific families, or bCoV for the families which are specific to the betacoronavirus clade, which SARS-CoV-2 belongs to. We have also fixed inconsistencies in the naming and descriptions of the various non-structural proteins, using NSPx for those proteins encoded by the replicase polyprotein, and NSx for those encoded by other ORFs. We are grateful to Philippe Le Mercier from the Swiss Institute of Bioinformatics who gave us valuable guidance for our nomenclature.

Where are the data?

You can access a small HMM library (Pfam-A.SARS-CoV-2.hmm) for all the Pfam families that match the SARS-CoV-2 protein sequences on the Pfam FTP site:

ftp://ftp.ebi.ac.uk/pub/databases/Pfam/releases/Pfam_SARS-CoV-2_1.0/

You can also find a file (matches.scan) showing the matches of the models against the SARS-CoV-2 sequences in the same FTP location. These updates are not yet available on the Pfam website. We anticipate making them available in 6-8 weeks.  We hope you find our SARS-CoV-2 models useful for your research, and as always we welcome your feedback via email at pfam-help@ebi.ac.uk.

How to use this library?

This library is not compatible with the pfam_scan software that we normally recommend to reproduce Pfam matches, as this library only contains a small subset of models.  If you wish to compare these models to your own sequences, please use the following HMMER commands:

$ hmmpress  Pfam-A.SARS-CoV-2.hmm

This only needs to be performed once. Then to compare your sequences (in a file called my.fasta) to this special Pfam profile HMM library, then:

$ hmmscan --cut_ga --domtblout matches.scan Pfam-A.SARS-CoV-2.hmm my.fasta

The –domtblout option enables you to save the matches in a more convenient tabular form, if you do not want to parse the HMMER output.

And finally

We will be making Pfam alignments available during the next week and will produce another blog post describing them.

Posted by The Pfam team

We are recruiting!

August 7, 2019

We have two biocurator positions available to work on the Pfam and InterPro databases. Come and join our team!

The main role of the jobs will be to:

  • Create and maintain InterPro and Pfam entries through the assessment of protein signature models. This will involve using our curation interfaces and tools (using basic command line)
  • Write descriptive abstracts of protein families and domains, summarizing functional information found within the scientific literature.
  • Augment entries with annotation terms for use in automatic annotation pipelines, for example the use of GO annotations and other data standards.
  • Respond to user and collaborator queries and requests.
  • Help develop and deliver training materials, either in person or via the Train Online platform

 

Full details can be found on the EBI jobs pages:

https://www.embl.de/jobs/searchjobs/index.php?ref=EBI01490

https://www.embl.de/jobs/searchjobs/index.php?ref=EBI01418

 

If you have any questions, please get in touch.

 

Posted by Jaina and Lorna

Pfam 31.0 is released

March 8, 2017

Pfam 31.0 contains a total of 16712 families and 604 clans. Since the last release, we have built 415 new families, killed 9 families and created 11 new clans.  We have also been working on expanding our clan classification; in Pfam 31.0, over 36% of Pfam entries are placed within a clan. Read the rest of this entry »

Pfam train online

December 8, 2016

We now have an online Quick Tour that provides a brief introduction to the Pfam protein families database. It provides a basic description of Pfam, as well as advice on how to search the database and discover protein-related information. The tour also showcases various tools that allow users to visualize data in Pfam, and explains where to find out more about the resource. We recommend taking the tour to learn how to use Pfam effectively.

Pfam Quick Tour

Pfam 30.0 is available

July 1, 2016

Pfam 30.0, our second release based on UniProt reference proteomes, is now available. The new release contains a total of 16,306 families, with 22 new families and 11 families killed since the last release. The UniProt reference proteome set has expanded and now includes 17.7 million sequences, compared with 11.9 million when we made Pfam 29.0. In this release, we have updated the annotations on hundreds of Pfam entries, and renamed some of our Domains of Unknown Function (DUF) families.

DUFs are protein domains whose function is uncharacterised. Over time, as scientific knowledge increases and new data about proteins comes to light, more information about the function of a domain may become available. As a result, DUFs can be renamed and re-annotated with more meaningful descriptions. As part of Pfam 30.0, we have re-annotated 116 DUFs based on updated information in the UniProtKB database, the scientific literature, and feedback from Pfam and InterPro users. Examples of some our DUF updates in Pfam 30.0 are given below:

 

  • PF10265, created in release 23.0 and originally named DUF2217, has been renamed to Miga, a family of proteins that promote mitochondrial fusion.
  • PF10229, created in release 23.0 and originally named DUF2246, has been renamed as MMADHC, as it represents methylmalonic aciduria and homocystinuria type D proteins and their homologues.  The structure of this domain is shown below.

 

5cv0

Structure of MMADHC dimer, PDB:5CV0

 

  • PF12822, created in release 25.0 and originally named DUF3816, has been renamed to ECF_trnsprt, since it contains proteins identified as the substrate-specific component of energy-coupling factor (ECF) transporters.

Please note that we may change the identifier for a family (e.g. DUF2217), but we never change the accession for a family (e.g. PF10265).

If you find any more DUFs that can be assigned a name based on function, or any other annotation updates, please get in touch with us (pfam-help@ebi.ac.uk).

 

Pfam 29.0 is now available

December 22, 2015

Pfam 29.0, our second release of 2015, contains 16295 entries and 559 clans. We have made some major changes to our underlying sequence database and the data that are displayed on the website, which we’ve outlined below. Full details can be found in our Nucleic Acids Research paper, which is available here. Read the rest of this entry »

Moving to xfam.org

May 1, 2014

Back in November 2012 we announced that the Xfam team in the UK was moving from the Wellcome Trust Sanger Institute to the European Bioinformatics Institute (EMBL-EBI), just next door on the Wellcome Trust Genome Campus. On Tuesday we completed that move by switching off the Pfam and Rfam websites inside Sanger and redirecting all traffic to our shiny new home at xfam.org. You can now find the Pfam and Rfam websites at pfam.xfam.org and rfam.xfam.org respectively. Read the rest of this entry »