---
license: cc-by-4.0
task_categories:
  - text-generation
language:
  - en
tags:
  - protein-structure
  - alphafold
  - structural-biology
size_categories:
  - 1M<n<10M
---

# AFDB-1.6M — One Representative Structure Per Structural Cluster

A deduplicated subset of [AFDB-24M](https://huggingface.co/datasets/timodonnell/afdb-24M), containing approximately 1.6 million AlphaFold Database predicted protein structures — one per structural cluster.

## How This Dataset Was Created

This dataset was derived from [AFDB-24M](https://huggingface.co/datasets/timodonnell/afdb-24M) using the following procedure:

1. All ~24 million rows across 12,005 shards were scanned.
2. Rows were grouped by `struct_cluster_id` (structural cluster representative from AFDB Foldseek clustering).
3. For each unique `struct_cluster_id`, the single row with the **highest `global_plddt`** (global mean pLDDT confidence score) was selected.
4. The selected rows were written into new Parquet shards (2,000 rows each, ZSTD level 12 compression).

This yields approximately 1.6 million entries — one high-confidence representative per 3D structural fold cluster.

## Dataset Summary

| Property | Value |
|----------|-------|
| Source | [AFDB-24M](https://huggingface.co/datasets/timodonnell/afdb-24M) |
| Total entries | ~1.6M (one per `struct_cluster_id`) |
| Selection criterion | Highest `global_plddt` per structural cluster |
| Format | Apache Parquet, ZSTD compressed (level 12) |
| Splits | train (98%), val (1%), test (1%) — inherited from AFDB-24M |

## Schema

Each Parquet file contains a flat table with the following columns (same schema as AFDB-24M):

| Column | Type | Description |
|--------|------|-------------|
| `entry_id` | `string` | AFDB entry ID (e.g., `AF-A0A1C0V126-F1`) |
| `uniprot_accession` | `string` | UniProt accession (e.g., `A0A1C0V126`) |
| `tax_id` | `int64` | NCBI taxonomy ID |
| `organism_name` | `string` | Scientific name of the organism |
| `global_plddt` | `float32` | Global mean pLDDT confidence score (70–100) |
| `seq_len` | `int32` | Sequence length in residues |
| `seq_cluster_id` | `string` | AFDB50 sequence cluster representative entry ID |
| `struct_cluster_id` | `string` | Structural cluster representative entry ID |
| `split` | `string` | `train`, `val`, or `test` |
| `gcs_uri` | `string` | Original GCS URI |
| `cif_content` | `string` | Complete raw mmCIF file text |

## Usage

### Loading with PyArrow

```python
import pyarrow.parquet as pq

table = pq.read_table("shard_000000.parquet")
print(table.schema)
print(f"{len(table)} rows")
```

### Loading with Pandas

```python
import pandas as pd

df = pd.read_parquet("shard_000000.parquet")
print(df[["entry_id", "organism_name", "global_plddt", "seq_len", "split"]].head())
```

### Parsing Structures with Gemmi

```python
import gemmi

row = table.to_pydict()
cif_text = row["cif_content"][0]
doc = gemmi.cif.read_string(cif_text)
structure = gemmi.make_structure_from_block(doc.sole_block())
model = structure[0]
chain = model[0]
print(f"{len(chain)} residues")
```

## Data Source and License

- **AlphaFold Database** structures are provided by DeepMind and EMBL-EBI under [CC BY 4.0](https://creativecommons.org/licenses/by/4.0/).
- **Cluster files** are from the [Steinegger lab](https://afdb-cluster.steineggerlab.workers.dev/), based on Foldseek clustering of AFDB v4 (Version 3 clusters).

### Citation

If you use this dataset, please cite the AlphaFold Database:

```bibtex
@article{varadi2022alphafold,
  title={AlphaFold Protein Structure Database: massively expanding the structural coverage of protein-sequence space with high-accuracy models},
  author={Varadi, Mihaly and Anyango, Stephen and Deshpande, Mandar and others},
  journal={Nucleic Acids Research},
  volume={50},
  number={D1},
  pages={D439--D444},
  year={2022},
  doi={10.1093/nar/gkab1061}
}
```

And the AFDB cluster resource:

```bibtex
@article{barrio2024clustering,
  title={Clustering predicted structures at the scale of the known protein universe},
  author={Barrio-Hernandez, Inigo and Yeo, Jimin and Jänes, Jürgen and others},
  journal={Nature},
  volume={622},
  pages={637--645},
  year={2023},
  doi={10.1038/s41586-023-06510-w}
}
```