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Overview

AlphaFold 3 requires multiple genetic and structural databases for generating multiple sequence alignments (MSAs) and structural templates. These databases enable the model to leverage evolutionary information.
Total size: ~252 GB compressed, ~630 GB uncompressed. Plan for sufficient storage and bandwidth.

Required Databases

AlphaFold 3 uses the following databases:

Protein Databases

BFD Small

Modified BFD (Big Fantastic Database)Clustered protein sequences for fast MSA generationVersion: 2022-09-28

MGnify

Metagenomic sequencesProtein sequences from metagenomics studiesVersion: 2022_05

UniProt

Universal Protein ResourceComprehensive protein sequence databaseVersion: 2021_04

UniRef90

UniProt Reference Clusters90% identity clustered UniProt sequencesVersion: 2022_05

RNA Databases

NT-RNA

Nucleotide RNAClustered RNA sequences from NCBIVersion: 2023_02_23

RFam

RNA familiesRNA sequence families databaseVersion: 14_9

RNACentral

RNA sequence databaseComprehensive RNA sequence collectionVersion: 21_0

Structural Databases

PDB mmCIF

Protein Data Bank structures~200,000 structures in mmCIF formatVersion: 2022-09-28

PDB Seqres

PDB sequencesSequence database for template searchVersion: 2022-09-28

Quick Installation

Automated Download Script

AlphaFold 3 provides a download script that fetches all required databases:
path
default:"$HOME/public_databases"
Target directory for databases. Must NOT be inside AlphaFold 3 repository.

Prerequisites

Running in Screen/Tmux

Download takes ~45 minutes on fast connections. Use screen or tmux for long-running processes.

Manual Installation

If you prefer manual download or need specific versions:

Protein Databases

Size: ~17 GB compressed, ~65 GB uncompressed

RNA Databases

Size: ~8 GB compressed, ~30 GB uncompressed

Structural Databases

Size: ~200,000 files, ~60 GB

Directory Structure

After installation, your database directory should look like:

Storage Optimization

Using SSD for Performance

Genetic search is I/O intensive. SSD storage provides 10-100× speedup over HDD.

Copying to SSD

Using RAM Disk (Maximum Performance)

RAM disk contents are lost on reboot. Only for temporary high-performance scenarios.

Partial SSD Setup

Use SSD for frequently accessed databases, HDD for others:
AlphaFold 3 checks SSD first, falls back to HDD.

Database Sharding

For high-throughput environments with many CPU cores:

Why Shard?

Sharding enables parallel genetic search across many CPU cores, dramatically reducing wall-clock time.
Benefits:
  • Utilize 32+ core systems effectively
  • Reduce genetic search time by 10-50×
  • Maximize disk I/O parallelization

Sharding Process

1

Install seqkit

2

Shuffle Sequences

Random shuffling ensures balanced shard sizes.
3

Split into Shards

Output: uniref90_shuffled.fa.split/uniref90_shuffled.part_001.fa, etc.
4

Rename with Padding

5

Count Sequences/Bases

Save these values for Z-value flags.

Using Sharded Databases

shard_count
Specifies 128 shards with pattern uniref90.fasta-XXXXX-of-00128
integer
Total sequence count across all shards (for e-value scaling)
integer
Maximum shards to process in parallel
For consistent performance, aim for equal shard sizes (~0.5-2 GB per shard).

Permissions and Access

Setting Permissions

Improper permissions cause opaque MSA tool errors. Ensure full read/write access.

Docker Mounts

Use :ro (read-only) suffix for safety.

Singularity Binds

Verifying Installation

Check Files Exist

Test with AlphaFold

Successful run confirms database setup.

Database Updates

AlphaFold 3 uses specific database versions from the paper. Newer versions may work but are not officially supported.
Using different database versions may affect prediction quality and reproducibility.
If you must update:
  1. Download new version to separate directory
  2. Test with known inputs
  3. Compare results to original databases
  4. Update --db_dir flags

Troubleshooting

Download Interrupted

Corrupted Files

Insufficient Space

Permission Errors

MSA Tools Can’t Find Databases

Database Licenses

All databases are available under permissive licenses:
  • BFD: CC BY 4.0
  • MGnify: CC0 1.0
  • PDB: CC0 1.0
  • UniProt/UniRef: CC BY 4.0
  • NT-RNA: Modified (see paper)
  • RFam: CC0 1.0
  • RNACentral: CC0 1.0
See AlphaFold 3 README for full attribution.

Next Steps

Performance

Optimize database access and search speed

Running Docker

Use databases with AlphaFold 3