# 2s.io UniProtKB Protein Lookup

> 2s.io UniProtKB Protein Lookup is a paid API for AI agents from 2s.io, paid per call via x402, $0.00144/call, status unknown (last checked 2026-09-14).

Look up detailed protein metadata from UniProtKB by accession number, returning names, gene info, organism, sequence, function, structure, and ontology data.

## Facts

- Endpoint: GET https://2s.io/api/bio/protein
- Price: $0.00144/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/2s-io-uniprotkb-protein-lookup-2a3b12f0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_HdC_UARHR_4zgEEVATkdL

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability 2s-io-uniprotkb-protein-lookup-2a3b12f0
```

Example prompt: Can you look up the UniProt entry for accession P04637 — I need its recommended protein name, gene name, organism, function description, subcellular locations, Gene Ontology terms, and any associated PDB structure IDs.

## When to prefer this

Use this endpoint when you need rich, curated protein metadata — including function, GO terms, structure IDs, and subcellular localization — from UniProtKB given a known accession. Prefer this over gene-centric endpoints when your identifier is a UniProt accession rather than a gene symbol. Best for bioinformatics pipelines, drug target research, structural biology lookups, and educational queries about specific proteins.

## Known failure modes

- Invalid or unrecognized accession returns 404 or empty result
- Accession typo causes no match
- Protein exists but is unreviewed (TrEMBL) — some fields may be sparse
- Transient upstream UniProt data unavailability causes timeout or 5xx
- Rate limiting or payment failure returns 402 or 429

## How this service works

Look up a protein in UniProtKB by accession (e.g. "P04637", "Q9Y6K9", "P0DTC2"). Returns the entry id, reviewed (Swiss-Prot) flag, recommended + alternative protein names, gene names, organism + taxid, sequence length and molecular weight, the curated function description, subcellular locations, Gene Ontology terms (id + term + aspect: biological_process / molecular_function / cellular_component), PDB structure ids, and keywords. Bioinformatics, structural biology, drug-target research, education. Gene-centric sibling: /api/bio/gene. CC-BY UniProt data.

## Output

Returns a structured record for the protein including: entry ID, whether it is Swiss-Prot reviewed, recommended and alternative protein names, gene names, organism with taxon ID, sequence length and molecular weight, curated function description, subcellular locations, GO terms with IDs and aspects (biological_process, molecular_function, cellular_component), PDB structure IDs, and keyword tags.

## Example request

```json
{
 "input": {
  "type": "http",
  "method": "GET",
  "queryParams": {
   "accession": "P04637"
  }
 }
}
```

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method",
    "queryParams"
   ],
   "properties": {
    "type": {
     "const": "http"
    },
    "method": {
     "const": "GET"
    },
    "queryParams": {
     "required": [
      "accession"
     ],
     "properties": {
      "accession": {
       "type": "string",
       "description": "UniProtKB accession, e.g. \"P04637\"."
      }
     }
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/2s-io-uniprotkb-protein-lookup-2a3b12f0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from 2s.io](https://www.zero.xyz/host/2s.io/llms.txt)