# RCSB PDB 3D Protein Structure Lookup

> RCSB PDB 3D Protein Structure Lookup is a paid API for AI agents from bio.memoryapi.org, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Retrieves 3D protein structure data from the RCSB Protein Data Bank (PDB), including PDB ID, title, experimental method, resolution, chains, and molecular weight.

## Facts

- Endpoint: GET https://bio.memoryapi.org/x402/bio/structure
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/bio-memoryapi-org-cd885bdd
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_B5EDiZlMBg-1oO-EQnvip

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 bio-memoryapi-org-cd885bdd
```

Example prompt: Can you pull up the PDB structure entry for 1HHO — I need the title, experimental method, resolution, chain composition, and molecular weight from the RCSB Protein Data Bank.

## When to prefer this

Use this endpoint when an agent needs structural biology metadata — specifically PDB ID, experimental details, resolution, chain composition, or molecular weight — directly from the RCSB PDB. Prefer this over UniProt endpoints when the user is interested in 3D structure properties rather than sequence or functional annotation.

## Known failure modes

- Invalid or non-existent PDB ID returns an error or empty result
- Network timeout if PDB upstream is slow
- Malformed PDB ID format rejected with 4xx response
- Deprecated or obsolete PDB entries may return partial data

## How this service works

RCSB PDB 3D protein structure data — PDB ID, title, experimental method, resolution, chains, molecular weight.

## Output

Returns structured metadata for the queried PDB entry, including the PDB ID, full structure title, experimental method (e.g. X-ray crystallography, cryo-EM), resolution in Angstroms, list of polypeptide chains, and molecular weight of the macromolecular assembly.

## Example request

```json
{
 "name": "metformin",
 "type": "label"
}
```

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "properties": {
    "method": {
     "type": "string",
     "enum": [
      "GET"
     ]
    }
   },
   "required": [
    "method"
   ]
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/bio-memoryapi-org-cd885bdd/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from bio.memoryapi.org](https://www.zero.xyz/host/bio.memoryapi.org/llms.txt)