ESM3Di

ESM + PEFT LoRA for 3Di per-residue prediction. Train ESM-2 or ESM++ models with LoRA adapters to predict 3Di structural sequences from amino acid sequences.

Try It Online

No installation required! Run ESM3Di directly in Google Colab with GPU support:

→ Open ESM3Di in Colab

The Colab notebook allows you to:

• Predict 3Di sequences from amino acid FASTAs
• Choose between ESM2 and ESM++ models
• Download results as FASTA files
• Create FoldSeek databases

Features

• 🧬 Train ESM-2 and ESM++ models for 3Di structure prediction
• 🎯 Memory-efficient training using LoRA (Low-Rank Adaptation)
• 🔧 Support for masking low-confidence positions
• ⚡ Multi-GPU training with DataParallel
• 🔀 Multi-GPU inference with automatic sharding
• 🌐 Google Colab notebook for online inference

Installation

Option 1: Using Conda (Recommended)

1. Create and activate the conda environment:

# Standard environment (CUDA 11.8, most GPUs):
conda env create -f environment.yml
conda activate esm3di

# For Blackwell GPUs (RTX 5090, RTX PRO 4000, etc.):
conda env create -f environment_blackwell.yml
conda activate esm3di_blackwell

Note: For exact reproducibility, use environment_frozen.yml which has pinned versions.

Option 2: Using pip

1. Create a virtual environment:

python -m venv venv
source venv/bin/activate  # On Windows: venv\Scripts\activate

2. Install dependencies:

pip install -r requirements.txt
pip install -e .

Usage

Downloading Test Structures from AlphaFold Database

Download random AlphaFold structures for testing or training:

python -m esm3di.testdataset \
    --count 10 \
    --output-dir test_structures \
    --seed 42

Or download specific proteins by UniProt accession:

python -m esm3di.testdataset \
    --accessions P04637 P01112 P42574 \
    --output-dir structures

Download Options

• --count: Number of random structures to download
• --accessions: Specific UniProt accessions to download
• --output-dir: Output directory (default: alphafold_structures)
• --delay: Delay between downloads in seconds (default: 0.5)
• --seed: Random seed for reproducible sampling
• --version: AlphaFold model version (default: 4)

Note: Downloaded structures are from the AlphaFold Protein Structure Database

Building Training Dataset from PDB Files

Generate training data from PDB structures with pLDDT-based masking:

python -m esm3di.build_trainingset \
    --pdb-dir alphafold_structures/ \
    --output-prefix training_data \
    --plddt-threshold 70 \
    --mask-char X

This will:

1. Parse PDB files to extract sequences and pLDDT scores (from B-factor column)
2. Use FoldSeek to generate 3Di sequences
3. Mask low-confidence positions (pLDDT < threshold) in 3Di sequences
4. Output AA and masked 3Di FASTA files ready for training

Building Training Set Options

• --pdb-dir: Directory containing PDB files (or use --pdb-files for specific files)
• --output-prefix: Prefix for output files
• --plddt-threshold: pLDDT threshold below which to mask (default: 70)
• --mask-char: Character for masking low-confidence positions (default: X)
• --split-chains: Split multi-chain structures into separate entries
• --chain: Extract specific chain only

Output files:

• {prefix}_aa.fasta: Amino acid sequences
• {prefix}_3di_masked.fasta: 3Di sequences with masked positions
• {prefix}_stats.txt: Statistics about masking

Training

Train a model using FASTA files with amino acid sequences and corresponding 3Di labels:

python -m esm3di.esmretrain \
    --aa-fasta data/sequences.fasta \
    --three-di-fasta data/3di_labels.fasta \
    --hf-model facebook/esm2_t33_650M_UR50D \
    --mask-label-chars "X" \
    --batch-size 4 \
    --epochs 10 \
    --lr 1e-4 \
    --out-dir checkpoints/

Using ESM++ Models

ESM++ models from Synthyra (via HuggingFace) are supported and offer improved performance:

# Train with ESM++ Small (333M params)
python -m esm3di.esmretrain \
    --aa-fasta data/sequences.fasta \
    --three-di-fasta data/3di_labels.fasta \
    --hf-model Synthyra/ESMplusplus_small \
    --mask-label-chars "X" \
    --batch-size 4 \
    --epochs 10 \
    --lr 2e-4 \
    --out-dir checkpoints/

# Or use ESM++ Large for better quality
python -m esm3di.esmretrain \
    --hf-model Synthyra/ESMplusplus_large \
    # ... other args

Available ESM++ Models:

• Synthyra/ESMplusplus_small: 333M parameters
• Synthyra/ESMplusplus_large: 575M parameters

ESM++ models provide:

• Better protein representations than ESM-2
• Faster inference
• Improved scaling and performance
• Native HuggingFace integration (no additional dependencies)

Key Arguments

• --aa-fasta: FASTA file with amino acid sequences
• --three-di-fasta: FASTA file with matching 3Di sequences (same order and length)
• --hf-model: Model identifier. ESM-2 options: facebook/esm2_t12_35M_UR50D (35M), facebook/esm2_t30_150M_UR50D (150M), facebook/esm2_t33_650M_UR50D (650M). ESM++ options: Synthyra/ESMplusplus_small (333M), Synthyra/ESMplusplus_large (575M)
• --mask-label-chars: Characters to treat as masked (e.g., low pLDDT positions)
• --lora-r: LoRA rank (default: 8)
• --lora-alpha: LoRA scaling factor (default: 16.0)
• --batch-size: Training batch size per GPU
• --epochs: Number of training epochs
• --lr: Learning rate
• --out-dir: Directory to save checkpoints
• --multi-gpu: Enable multi-GPU training (uses all available GPUs)
• --mixed-precision: Enable FP16 mixed precision training
• --gradient-accumulation-steps: Accumulate gradients over N batches

Multi-GPU Training

For training on multiple GPUs, use the --multi-gpu flag:

python -m esm3di.esmretrain \
    --aa-fasta data/sequences.fasta \
    --three-di-fasta data/3di_labels.fasta \
    --hf-model Synthyra/ESMplusplus_small \
    --batch-size 8 \
    --multi-gpu \
    --mixed-precision \
    --epochs 10 \
    --out-dir checkpoints/

This uses torch.nn.DataParallel to automatically distribute batches across all available GPUs. The effective batch size is batch_size * num_gpus.

Multi-GPU Training Options:

• --multi-gpu: Enable DataParallel multi-GPU training
• --mixed-precision: Enable FP16 for faster training and reduced memory
• --gradient-accumulation-steps: Simulate larger batches when GPU memory is limited
• --device: Specify primary GPU (e.g., cuda:0)

Example with gradient accumulation:

# Effective batch size = 4 * 4 * 2 GPUs = 32
python -m esm3di.esmretrain \
    --batch-size 4 \
    --gradient-accumulation-steps 4 \
    --multi-gpu \
    # ... other args

Using Config Files

For reproducible experiments, use JSON config files:

python -m esm3di.esmretrain --config config_esmpp_large.json

Example config file:

{
  "aa_fasta": "data/sequences.fasta",
  "three_di_fasta": "data/3di_labels.fasta",
  "hf_model": "Synthyra/ESMplusplus_small",
  "mask_label_chars": "X",
  "use_cnn_head": true,
  "batch_size": 8,
  "epochs": 3,
  "lr": 0.0002,
  "multi_gpu": true,
  "mixed_precision": true,
  "out_dir": "checkpoints_esmpp"
}

Inference

Use the trained model to predict 3Di sequences:

from esm3di import predict_3di_for_fasta

results = predict_3di_for_fasta(
    model_ckpt="checkpoints/epoch_10.pt",
    aa_fasta="data/test_sequences.fasta",
    device="cuda"  # or "cpu"
)

for header, aa_seq, pred_3di in results:
    print(f">{header}")
    print(f"AA:  {aa_seq}")
    print(f"3Di: {pred_3di}")

Creating FoldSeek Database

Generate a FoldSeek-compatible database from amino acid sequences:

python -m esm3di.fastas2foldseekdb \
    --aa-fasta data/proteins.fasta \
    --model-ckpt checkpoints/epoch_10.pt \
    --output-db my_foldseek_db

This will:

1. Run ESM inference to predict 3Di sequences
2. Create intermediate AA and 3Di FASTA files
3. Build a FoldSeek database with both sequence and structure information

Multi-GPU Inference

For large datasets, enable multi-GPU inference to parallelize predictions:

python -m esm3di.fastas2foldseekdb \
    --aa-fasta data/large_dataset.fasta \
    --model-ckpt checkpoints/epoch_10.pt \
    --output-db my_foldseek_db \
    --multi-gpu \
    --num-gpus 4

How Multi-GPU Inference Works:

1. Input sequences are sharded across GPUs using round-robin distribution
2. Each GPU runs as an isolated subprocess with its own CUDA context
3. Predictions are merged back into original sequence order
4. FoldSeek database is built from the merged results

Multi-GPU Inference Options:

• --multi-gpu: Enable multi-GPU inference
• --num-gpus: Number of GPUs to use (default: all available)

Using Pre-computed 3Di Sequences

If you already have 3Di predictions:

python -m esm3di.fastas2foldseekdb \
    --aa-fasta data/proteins.fasta \
    --three-di-fasta data/proteins_3di.fasta \
    --output-db my_foldseek_db \
    --skip-inference

FoldSeek Database Options

• --keep-fastas: Keep intermediate FASTA files after database creation
• --output-aa-fasta: Specify path for AA FASTA output
• --output-3di-fasta: Specify path for 3Di FASTA output
• --foldseek-bin: Custom path to foldseek binary

Note: FoldSeek must be installed and available in your PATH. Download from https://github.com/steineggerlab/foldseek

Data Format

Input FASTA Files

Both amino acid and 3Di FASTA files should have:

• Matching number of sequences
• Sequences in the same order
• Equal length for corresponding AA and 3Di sequences

Example sequences.fasta:

>protein1
MKTAYIAKQRQISFVKSHFSRQLEERLGLIEVQAPILSRVGDGTQDNLSGAEK
>protein2
KALTARQQEVFDLIRDHISQTGMPPTRAEIAQRLGFRSPNAAEEHLKALARKGVIE

Example 3di_labels.fasta:

>protein1
acbdACBDacbdACBDacbdACBDacbdACBDacbdACBDacbdACBDacbdA
>protein2
XbdACBDacbdACBDacbdACBDacbdACBDacbdACBDacbdACBDacbdACB

Note: Characters specified in --mask-label-chars (e.g., 'X') will be ignored during training.

Model Checkpoints

Checkpoints are saved after each epoch and contain:

• Model state dict (including LoRA adapters)
• Label vocabulary
• Masked label characters
• Training arguments

Downloading Pre-trained Checkpoints

Pre-trained checkpoints are hosted on HuggingFace Hub for easy access:

from huggingface_hub import hf_hub_download

# Download ESM2 35M checkpoint (~131MB)
checkpoint = hf_hub_download(
    repo_id="cactuskid13/esm2small_3di",
    filename="epoch_3.pt"
)

# Or download ESM++ BFVD checkpoint (~1.4GB)
checkpoint = hf_hub_download(
    repo_id="cactuskid13/ESMpp_small_3Di",
    filename="epoch_3.pt"
)

Available Pre-trained Checkpoints

HuggingFace Repository	Model	Size	Description
cactuskid13/esm2small_3di	ESM2 35M	~131MB	Fast, well-tested, recommended
cactuskid13/ESMpp_small_3Di	ESM++ small	~1.4GB	Trained on BFVD, better accuracy

Recommended for most users: cactuskid13/esm2small_3di (fast, small, reliable)

Verifying Predictions

Use the test script to verify that model outputs have sufficient diversity:

python test_output_diversity.py output_3di.fasta

This will check that:

• Output contains multiple unique 3Di characters
• No single character dominates more than 50% of predictions
• Output is not effectively uniform (>90% one character)

Requirements

• Python ≥ 3.8
• PyTorch ≥ 2.0.0
• transformers ≥ 4.30.0
• peft ≥ 0.5.0
• CUDA-capable GPU (recommended)
• biopython (for FoldSeek database creation)

For multi-GPU training/inference:

• Multiple CUDA-capable GPUs
• Sufficient GPU memory (ESM++ small: ~4GB per GPU, ESM++ large: ~8GB per GPU)

License

MIT License

Citation

If you use this code, please cite the relevant papers:

• ESM-2: [Lin et al., 2022]
• ESM++: [Synthyra, 2024] - https://huggingface.co/Synthyra
• LoRA: [Hu et al., 2021]
• 3Di: [van Kempen et al., 2023]

Funding

Funded by NIH through the Pathogen Data Network.

*This resource is supported by the National Institute Of Allergy And Infectious Diseases of the National Institutes of Health under Award Number U24AI183840. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.