UniProt Search on the platform

UniProt Search lets you look up protein sequences and annotations — function, disease associations, GO terms, domains, and cross-references to PDB, ChEMBL, and AlphaFold. Reach for it to characterize a therapeutic target, retrieve a sequence for structure prediction, or navigate between databases by accession. It often follows a literature search: names extracted by PubMed or BioBERT become the terms you look up here. See the Databases overview for where this fits.

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What UniProt Search does

UniProt Search queries the Universal Protein Resource (UniProt), the most comprehensive protein knowledge base with over 250 million protein entries. UniProt is a collaboration between the European Bioinformatics Institute (EMBL-EBI), the Swiss Institute of Bioinformatics (SIB), and the Protein Information Resource (PIR). On the platform, UniProt Search provides direct API access to the UniProt REST API, returning protein records with functional annotations, sequences, and cross-references in 3-8 seconds.

UniProt consists of two main sections:

• UniProt/SwissProt: Manually reviewed, high-quality annotations (~570,000 entries). Entries are curated by expert biologists with experimental evidence.
• UniProt/TrEMBL: Computationally annotated entries (~250 million entries). Automatically generated from genome sequencing projects.

Citations

The UniProt Consortium. UniProt: the Universal Protein Knowledgebase in 2025. Nucleic Acids Research. 2025;53(D1):D609-D617. doi: 10.1093/nar/gkae1010

Key capabilities

• Protein lookup by accession: Retrieve a specific protein entry using its UniProt accession ID (e.g., P00533 for human EGFR)
• Gene-based search: Find proteins by gene symbol (e.g., TP53, BRCA1, EGFR)
• Free-text search: Search by protein name, function description, disease association, or any keyword
• Organism filtering: Restrict results to a specific species (all organisms unless you name one)
• Sequence retrieval: Get the full amino acid sequence for direct chaining into ESMFold or BLAST
• Feature annotation: Access domain annotations, post-translational modification sites, active sites, and binding sites
• Cross-reference mapping: Map between UniProt, PDB, ChEMBL, AlphaFold, Pfam, InterPro, and Gene IDs

How it works technically

UniProt Search on the platform wraps the UniProt REST API with two access patterns:

Direct accession lookup

When you provide a UniProt accession ID, the tool fetches the specific entry from https://rest.uniprot.org/uniprotkb/{accession}. This is the fastest path and returns the most complete data.

Search queries

When you provide a gene name or free-text query, the tool constructs a search against https://rest.uniprot.org/uniprotkb/search with Lucene-style query parameters. The search supports:

• Gene name queries: (gene:EGFR) AND (organism_name:"Homo sapiens")
• Free-text queries: (protein kinase inhibitor) AND (organism_name:"Homo sapiens")
• Combined queries with organism filtering

Response processing

The tool extracts and flattens key fields from UniProt's nested JSON response:

1. Identification: Accession, entry name, entry type (SwissProt vs. TrEMBL)
2. Protein description: Recommended name, alternative names
3. Gene information: Gene name, synonyms
4. Organism: Scientific name, common name, taxonomy ID
5. Function: Functional annotation, catalytic activity, pathway involvement
6. Disease associations: Known disease links with evidence codes
7. GO terms: Molecular function, biological process, cellular component annotations
8. Features: Domains, active sites, binding sites, PTMs, signal peptides
9. Sequence: Full amino acid sequence and length
10. Cross-references: PDB structures, ChEMBL targets, AlphaFold models, Pfam domains

When to use UniProt Search

Primary use cases

Target identification and characterization

• Look up a therapeutic target to understand its function, localization, and disease associations
• Retrieve the protein sequence for structure prediction with ESMFold
• Identify known PDB structures for the target via cross-references
• Assess druggability through domain and active site annotations

Protein sequence retrieval for downstream analysis

• Fetch sequences for ESMFold structure prediction
• Get sequences for BLAST similarity search
• Retrieve sequences for ESM-3 embedding generation
• Source sequences for molecular dynamics or docking workflows

Cross-database navigation

• Map a UniProt accession to PDB structure IDs
• Find ChEMBL target IDs for bioactivity queries
• Locate AlphaFold predicted structures
• Identify Pfam domain families and InterPro annotations

Target passport data sourcing

• UniProt annotations feed into Target Passport generation
• Function descriptions, disease associations, and druggability markers inform target assessment
• GO terms provide pathway and localization context

When to use alternatives

Integration with the platform ecosystem

Upstream data sources

UniProt Search accepts input from:

• Free-text chat queries: Protein names, gene symbols, or accession IDs
• BioBERT results: Protein and gene names extracted from literature
• PubMed Search: Target names identified in publications
• Entrez Gene: Gene IDs linked to UniProt accessions

Downstream applications

UniProt results feed into:

• ESMFold: Protein sequences for AI-based structure prediction
• BLAST: Sequences for similarity searching across databases
• ESM-3: Protein sequences for embedding generation
• AlphaFold Fetch: UniProt accessions for pre-computed structure retrieval
• DiffDock: Protein sequences or PDB cross-references for docking
• P2Rank: Structure-based binding site prediction
• Target Passport: Comprehensive target annotation aggregation

Workflow chaining examples

Target-to-structure pipeline:

1. UniProt Search for "human EGFR"
2. ESMFold for structure prediction (or PDB Search via cross-reference)
3. P2Rank for binding pocket prediction
4. DiffDock for ligand docking

Literature-to-target pipeline:

1. PubMed Search for disease-related publications
2. BioBERT entity extraction for protein names
3. UniProt Search for each extracted protein
4. Target Passport generation

Scope and limitations

Coverage

• SwissProt: ~570,000 manually curated entries with high-quality annotations
• TrEMBL: ~250 million computationally annotated entries
• Organisms: All sequenced organisms, with best coverage for model organisms
• Update frequency: Monthly major releases, with continuous updates between releases

Limitations

• TrEMBL quality: Automatically annotated entries may have incomplete or incorrect functional annotations. SwissProt entries are more reliable.
• Organism bias: Best annotation coverage for human, mouse, rat, and well-studied model organisms. Annotations for non-model organisms may be sparse.
• Isoform coverage: UniProt represents canonical sequences by default. Alternative isoforms exist but may not be returned unless specifically requested.
• Result limit: The platform returns up to 25 entries per search to keep response times fast. The full UniProt database may contain many more matches.
• Sequence length: Some very large proteins (>5000 residues) may cause downstream issues with structure prediction tools.

Performance characteristics

• Typical runtime: 3-8 seconds for accession lookup, 5-15 seconds for search queries
• Maximum results: 25 entries per query (5 by default; ask for more or fewer)
• Licensing: UniProt data is available under CC BY 4.0 (attribution required)

References

• UniProt: https://www.uniprot.org/
• UniProt REST API documentation: https://www.uniprot.org/help/api
• The UniProt Consortium. UniProt: the Universal Protein Knowledgebase in 2025. Nucleic Acids Res. 2025;53(D1):D609-D617. doi: 10.1093/nar/gkae1010

Chat Usage

Example Prompts

• "Search UniProt for human EGFR"
• "Get the sequence for P04637 from UniProt"
• "Find all human kinases in UniProt with GO term 'protein kinase activity'"

Workflow Chaining

• Feeds into: ESMFold (structure prediction), BLAST (similarity search), ESM-3 (embeddings), Target Passport
• Accepts from: BioBERT (extracted protein names), literature search results

FAQ

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