Sandra Orchard (V1.1 05/05/09) UniProtKB and InterPro - Annotating a protein sequence The Starting Point – a sequence (peptide or protein) MSEQSTSLGSRRVGPPLHKKALRVCFLRNGDRHFKGVNLVISRAHFKDFPALLQGVTESLKRH VLLRSAIAHFRRTDGSHLTSLSCFRETDIVICCCKNEEIICVKYSINKDFQRMVDSCKRWGQH HLDSGTLESMKSHDLPEAIQLYIETIEPVEHNTRTLIYRGQTRANRTKCTVKMVNKQTQSNDR GDTYMEAEVLRQLQSHPNIIELMYTVEDERYMYTVLEHLDCNMQKVIQKRGILSEADARSVMR CTVSALAHMHQLQVIHRDIKPENLLVCSSSGKWNFKMVKVANFDLATYYRGSKLYVRCGTPCY MAPEMIAMSGYDYQVDSWSLGVTLFYMLCGKMPFASACKNSKEIYAAIMSGGPTYPKDMESVM SPEATQLIDGLLVSDPSYRVPIAELDKFQFLAL Alignments BLAST (Basic Local Alignment Search Tool), finds regions of sequence similarity and gives functional and evolutionary clues about the structure and function of your novel sequence. WU-BLAST 2.0 and NCBI BLAST2 are distinctly different software packages, although they have a common lineage for some portions of their code, so the two packages do their work differently and obtain different results and offer different features. You can also check for vector contamination with Blast2 EVEC. Fasta can be very specific when identifying long regions of low similarity especially for highly diverged sequences. You can also conduct sequence similarity searching against complete proteome or genome databases using the Fasta programs. MPsrch – Smith and Waterman algorithm, capable of identifying hits in cases where Blast and Fasta fail and also reports fewer false-positive hits. For this exercise, we will use UniProt Blast This work is licensed under the Creative Commons Attribution-Share Alike 3.0 License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/ or send a letter to Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 94105, USA. 1 Paste your original sequence into BLAST, check Database = UniProtKB and “Blast” Scores should suggest a 100% match to Q9VCL7_DROME Click on the coloured bar to display aligned sequences On the right hand side of the display, find the series of check boxes headed Annotations and select Hydrophobic. Would you expect this protein to be transmembrane, looking at the distribution of its hydrophobic residues The UniProt Consortium is comprised of the European Bioinformatics Institute, the Swiss Institute of Bioinformatics and the Protein Information Resource. The UniProt consortium aims to support biological research by maintaining a high quality database that serves as a stable, comprehensive, fully classified, richly and accurately annotated protein sequence knowledgebase, with extensive cross-references and querying interfaces freely accessible to the scientific community. All data stored in UniProt can be downloaded from the Download Centre at http://www.ebi.uniprot.org/database/download.shtml. Click on hyperlinked Q9VCL7_DROME open UniProt entry. This is a UniProtKB/TrEMBL entry i.e. translated from the nucleotide sequence and only automatic annotation and additional cross-referencing added. Note Gene Name=Orf name – this will probably change when protein is characterised 2 Click on the taxonomy link to access organism detail. ? How many proteins are there in the Drosophila melanogaster complete proteome? Return back to the UniProtKB entry Scroll down to the cross-references Nucleotide Database – original submission data, identical underlying information stored in EMBL, Genbank and DDBJ but slightly different views. Ensembl/FlyBase – give a gene-centric view. FlyBase often contains additional literature references which may be of use. HSSP – Swiss Homology Model. For proteins lacking a PDB entry, gives most similar UniProtKB entry with a 3D structure. IntAct – Molecular Interaction Database IntAct is a freely available, open source database system and also provides analysis tools for protein interaction data. All interactions are derived from literature curation or direct user submissions and are freely available. Click on the hyperlinked Accession number in IntAct cross-reference line The protein has an interaction with annotated protein of known function – further details of the interaction could tell you more about your protein. ? Which proteins does your sequence interact with? IntAct stores an interaction in the context of the experimental method which described this interaction. If an interaction has been described several times using different methodologies, this will increase the “Number of Interactions” and also our confidence in the veracity of the interaction. Click on ‘Interaction AC’ to see details of experimental methodology We will return to IntAct later, but we will continue adding information to our existing Drosophila sequence. Return to UniProtKB entry 3 Searching UniProtKB Our protein is a kinase and a single Y2H experiment suggests it may interact with an ARF family protein. ?Are Arf family members regulated by phosphorylation? Search in UniProtKB for Arf family members using the text search Press on the ‘Fields’ button, select Field=Taxonomy and type ‘Drosophila melanogaster’ into the Term box. Add and Search Add Field = cross-reference, Database= InterPro and ‘IPR006689’ into the Term box (this is the ARF/SAR superfamily signature). Add and Search You should end up with a set of approximately 21 proteins Click on “reviewed” entries to limit this to Swiss-Prot entries Open P61209 (ARF1_DROME) – UniProtKB/Swiss-Prot entry. this is a fully annotated ? Scroll down to the feature table. Can you see any evidence that the protein is regulated by phosphorylation? (Hint – this information would be stored in the Sequence Annotation, if it were true). Interaction data is generated by a number of techniques, all of which are capable of generating False Positive data. It is possible that the single Y2H data point suggesting that there is an interaction between an Arf protein and a kinase may be incorrect. In the Swiss-Prot entry ARF1_DROME click on the link ‘Arf family’ under Comments – Sequence Similarity to find orthologous proteins in other species. Open Q3SXY8 (AR13B_HUMAN). This entry has two isoforms. Look what part of the molecule is missing in Isoform 2 and speculate on its 4 functional significance (Hint use the Sequence annotation (Features) field. InterPro Use InterproScan to assign family membership, identify functional domains etc. Paste the sequence given above into InterProScan (www.ebi.ac.uk/InterProScan), add e-mail address and “Submit Job” Looking at the results from InterProScan InterPro is an integrated documentation resource for protein families, domains and sites. InterPro combines a number of databases (referred to as member databases) that use different methodologies and a varying degree of biological information on well-characterised proteins to derive protein signatures. By uniting the member databases, InterPro capitalises on their individual strengths, producing a powerful integrated diagnostic tool. InterPro unifies: 5 · PROSITE regular expressions and profiles · Pfam, SMART, TIGRFAMs, PIRSF, PANTHER, SUPERFAMILY hidden Markov models (HMMs) Gene3D and · PRINTS, provider of fingerprints (groups of aligned, un-weighted motifs) . PRODOM who use Clustr analysis to group sequences Signatures describing the same protein family, domain repeat or site are grouped into unique InterPro entries. Each combined InterPro entry has a unique accession number, an abstract describing the features of proteins associated with the entry and literature references and has links to the relevant member database(s). All UniProtKB protein sequences that have matches to a particular InterPro entry are listed in the Match Table associated with that entry. There are also links to the InterPro graphical views. The graphical views, which can be sorted by UniProtKB accession number, structure or taxonomy, show the position of the signatures on the protein, mousing over the signature brings up a pop-box, giving the accession, name and position. InterPro graphically represents the location of a protein domain and information pertaining to the origin of that domain and the proteins that contain it. Families are also defined and may contain several InterPro domains which are often, but not always, in the same order. Through the InterPro Domain Architecture view, the composition and order of the different domains within a family are clearly displayed for easy comparison, as well as for simple navigation between the entries for individual domains. InterPro and InterProScan are accessible for interactive use over the EBI web server (www/ebi.ac.uk/interpro), they are distributed as stand-alone copies by anonymous ftp. InterPro entries are linked to one another through PARENT/CHILD and CONTAINS/FOUND IN relationships. PARENT/CHILD relationships indicate superfamily/family/subfamily relationships, as well as domain hierarchies, where sequences can be subdivided into more specific subsets. CONTAINS/FOUND IN relationships apply to domains, repeats and sites within families, and are used to describe the composition of protein sequences. ?What domains/sites does this protein contain? Tab through to raw output, check what positions these domains map to on the sequence (note – these will differ slightly between different databases) Click on IPR000719 to see what information you can gain about this domain. 6 ?What GO terms can you assign to your protein on the basis of InterPro signature recognition? Choose one GO term and copy/paste the GO ID into the text search box at the top of the InterPro entry page to list all the InterPro entries associated with this GO term. ?Returning to the IPR000719 entry page, what relationships does this entry have with other InterPro entries? At the top of the page are a number of different views possible for the proteins within this entry. Type O15075 or DCLK1_HUMAN into the InterPro search box (NOT the EBI-eye search), and scroll down to look at the domains contained within its various isoforms (yellow background). ? Why are isoforms -3 and -4 significantly different from -1 and -2. Looking back at DCLK1_HUMAN (O15075), this has a PDB structure (green striped bar) for its doublecortin domain. Note the classification of this domain in CATH (pink striped bar) and in SCOP (black striped bar). The kinase domain has a structural homology domain predicted by ModBase (yellow striped bar). Click on the hyperlink MB_O15075 to look at the predicted structure Have a look at the structure of the doublecortin domain using Astexviewer®, by clicking on the symbol adjacent to the first CATH domain (3.10.20.230.1). Remaining in line view, scroll along the sequence to residue 20 (Y - tyrosine) and clink on ‘Y’. This will zoom in and identify the residue on the structure. ? Is this residue buried or on the external surface of the protein? Click on the adjacent residue, but this time clicking on the structure itself. ?What residue is the tyrosine adjacent to? Now zoom out again, and have a look at the structure using the ribbon view by clicking on ‘cartoon’. ?What is the predominant topology of this protein, alpha helix or beta sheet (note: you can depress your left mouse button whilst moving the mouse to rotate the structure to any angle you want in order to get a better view of the structure). 7 Returning to the InterProScan page, click on IPR003533 ?What additional information can you gain about this protein? Are isoforms –3 and –4 of DCLK1_HUMAN likely to differ functionally from –1 and –2 (hint read the abstract). Move down to the taxonomy wheel and open the other fruit fly sequences which contain this domain. ? Is this domain only present in kinases? Homology to other related proteins is another powerful tool for information on a particular protein. Further Reading The UniProt Consortium (2011) Ongoing and future developments at the Universal Protein Resource.. Nucleic acids research, (39), d214-219 8 Leinonen R, Nardone F, Zhu W, Apweiler R “UniSave: the UniProtKB sequence/annotation version database.” Bioinformatics (2006) 22:1284-1285 Suzek BE, Huang H, McGarvey P, Mazumder R, Wu CH “UniRef: comprehensive and non-redundant UniProt reference clusters.” Bioinformatics (2007) 23:1282-1288 Hunter, S et al “InterPro: the integrative protein signature database..” Nucleic Acids Res. (2009) 36:D211-215 McDowall J , Hunter S (2011) InterPro protein classification. Methods Mol Biol 694:37-47 Aranda, B. et al “The IntAct molecular interaction database in 2010.” Nucleic Acids Res. (2010)38:D525-531