Ready to predict your first protein structure with AlphaFold2? This comprehensive guide will walk you through every step of the process, from preparing your sequence to analyzing the results.
#Before You Begin
Before running your first prediction, ensure you have:
- Your protein sequence in FASTA format
- A clear understanding of your research question
- Access to AlphaFold2 (via Protogen Bio or other platforms)
Sequence Quality Check
Make sure your sequence doesn't contain ambiguous amino acids (like 'X') and is free of gaps or special characters.
#Step-by-Step Prediction Guide
1. Preparing Your Sequence
Start with a clean FASTA file:
bash
>my_protein
MKTAYIAKQRQISFVKSHFSRQLEERLGLIEVQAPILSRVGDGTQDNLSGAEKAVQVKVKALPDAQFEVVHSLAKWKRQTLGQHDFSAGEGLYTHMKALRPDEDRLSPLHSVYVDQWDWERVMGDGERQFSTLKSTVEAIWAGIKATEAAVSEEFGLAPFLPDQIHFVHSQELLSRYPDLDAKGRERAIAKDLGAVFLVGIGGKLSDGHRHDVRAPDYDDWSTPSELGHAGLNGDILVWNPVLEDAFELSSMGIRVDADTLKHQLALTGDEDRLELEWHQALLRGEMPQTIGGGIGQSRLTMLLLQLPHIGQVQAGVWPAAVRESVPSLL2. Submitting Your Prediction Job
When submitting your job, you'll typically need to choose:
- Model: AlphaFold2 or AlphaFold2-Multimer (for complexes)
- Database: Full or reduced MSA databases
- Number of models: Usually 5 models for best results
Run Your First Prediction
Use Protogen Bio's platform to get started with AlphaFold2
3. Monitoring Your Job
AlphaFold2 predictions typically take:
- Small proteins (<100 residues): 10-30 minutes
- Medium proteins (100-500 residues): 30-90 minutes
- Large proteins (500+ residues): 1-3 hours
Processing Time
Most of the time is spent generating the MSA (Multiple Sequence Alignment), not the actual structure prediction.
#Understanding Your Results
What You'll Get
A completed AlphaFold2 job provides several important files:
- PDB files: 5 models (ranked by confidence)
- pLDDT scores: Per-residue confidence scores
- PAE matrix: Predicted Aligned Error for domain analysis
- MSA coverage: Information about sequence homologs found
First Look at Your Structure
When viewing your predicted structure, look for:
- Color coding: Blue (high confidence) to red (low confidence)
- Overall fold: Does it look like a real protein?
- Disordered regions: Flexible loops often have lower confidence
#Quality Assessment
Key Confidence Metrics
Good Prediction Indicators
- pLDDT > 90 for core regions
- Compact PAE matrix with dark blue blocks
- Good MSA coverage (>100 sequences)
Warning Signs
- Large regions with pLDDT < 70
- PAE matrix showing bright yellow/green patterns
- Poor MSA coverage (<30 sequences)
#Next Steps
After your first successful prediction, consider:
- Validating results against known experimental structures (if available)
- Using the structure for downstream applications (docking, design, etc.)
- Learning to interpret PAE matrices for domain analysis
- Exploring multimer predictions if you're studying protein complexes
Ready to Get Started?
Launch your first AlphaFold2 prediction on Protogen Bio
