The basic workflow
There are three routes to an AlphaFold structure, depending on your protein and your needs:
Route A: AlphaFold Database
Your protein is already predicted. Search by name or UniProt ID, download the structure, done. Free, instant, no computation needed.
Route B: AlphaFold Server
Run a prediction on AlphaFold's official server at alphafoldserver.com. Handles AlphaFold 3 including complexes. Free, limited to 20 jobs/day.
Route C: ColabFold
Run AlphaFold 2 (or variants) in a Google Colab notebook. More control, can run your own sequences, runs on Google's free GPUs. Takes ~15–60 min.
Start with Route A. Most proteins from common model organisms (human, mouse, yeast, E. coli, Arabidopsis, fly, worm, zebrafish) are already in the database. Only proceed to B or C if your protein isn't there, or you need a complex prediction.
Finding your protein on UniProt
UniProt (Universal Protein Resource) is the primary database of protein sequences
and annotations. Every protein has a unique UniProt accession ID — a short code like
P00533 (human EGFR) or P68871 (human haemoglobin beta chain).
This ID is what the AlphaFold database uses to organise entries.
Go to uniprot.org
The main search bar accepts protein names, gene names, or organism-specific names. Try "BRCA2 human" or "p53 human" to get started.
Choose the right entry
UniProt has two divisions: Swiss-Prot (manually reviewed, marked with a gold star — prefer these) and TrEMBL (computationally annotated). Filter by "Reviewed (Swiss-Prot)" for better-annotated entries.
Note the accession ID
The 6-character alphanumeric code (e.g., P04637 for TP53) is what you'll use to search the AlphaFold database and other tools.
Look at the sequence length
Note how many amino acids the protein has. AlphaFold 2 handles sequences up to about 2,700 residues well; longer proteins may need to be split into domains or require more resources.
Checking the AlphaFold database
Go to alphafold.ebi.ac.uk
The main AlphaFold Protein Structure Database, hosted by EMBL-EBI. The search bar accepts UniProt IDs, gene names, or protein names.
Search for your protein
Try the UniProt accession ID you found in Step 1. Or just type the protein name — e.g. "TP53" or "haemoglobin beta".
Read the confidence
The database page shows the structure coloured by pLDDT by default. Look at which regions are dark blue (high confidence) vs. orange (low confidence) before drawing any conclusions.
Download the structure
Click "Download" to get the PDB file (for most software) or mmCIF file (for newer tools). Also download the PAE JSON file if you need inter-domain confidence information.
ColabFold: AlphaFold in a Colab notebook
ColabFold (developed by Milot Mirdita, Martin Steinegger, and colleagues) provides AlphaFold 2 and RoseTTAFold predictions through Google Colab notebooks — free Jupyter notebooks that run on Google's cloud computers with free GPU access.
ColabFold is faster than vanilla AlphaFold (uses a faster MSA search method called MMseqs2) and significantly easier to run — no local installation required.
Open the ColabFold notebook
Go to colab.research.google.com and search for "ColabFold AlphaFold2", or find it directly at the ColabFold GitHub repository. You'll need a Google account.
Connect to a GPU runtime
In Colab: Runtime → Change runtime type → Hardware accelerator: GPU. This gives you access to a free GPU (T4 or similar) for your computation.
Enter your sequence
Paste your protein's amino acid sequence (one-letter code, like MTEYKLVVVGAGGVGKSALT...) into the query_sequence field. Give it a name in the jobname field.
Run all cells
Runtime → Run all. The notebook will: build the MSA (5–15 min), run AlphaFold (10–30 min depending on protein length), and generate output files. Don't close the tab while it runs.
Download outputs
ColabFold produces: PDB files for each model (usually 5 models ranked by confidence), pLDDT plots, PAE plots, and a summary JSON. Download the full output ZIP from the Files panel.
AlphaFold Server: official predictions including AlphaFold 3
Google DeepMind provides an official prediction server at alphafoldserver.com.
This uses AlphaFold 3 and is the only free way to get AlphaFold 3 predictions for complexes
(protein + DNA, protein + RNA, protein + small molecule).
Limits: Free accounts are limited to 20 jobs per day. Commercial use of the server is restricted under the terms of service — it's intended for non-commercial academic research.
For protein-only predictions, the database and ColabFold are usually more convenient. Use the server when you specifically need AlphaFold 3 features (complex prediction, ligand binding).
Visualising structures in Mol*
Mol* (pronounced "mol-star") is a modern, web-based 3-D molecular viewer developed by RCSB PDB, PDBe, and others. It runs in your browser with no installation required and handles large structures well.
Open Mol*
Go to molstar.org/viewer or use the embedded viewer on the AlphaFold database page.
Load your file
Drag and drop your downloaded PDB file onto the viewer, or use Open → Open Files. The structure will appear coloured by chain by default.
Colour by pLDDT
In the right panel, find the colour scheme. Select "Uncertainty/Disorder" or "B-factor" to colour by the pLDDT values stored in the B-factor column. Now you see confidence directly on the structure.
Explore representations
Switch between cartoon (ribbon), ball-and-stick (atoms), and surface representations using the Components panel. Surface representation is useful for seeing binding pockets.
Alternative visualisation tools
PyMOL
The gold standard for structural biology figures. Publication-quality images, highly scriptable. Free open-source version available; commercial version adds features.
pymol.org ↗UCSF ChimeraX
Excellent for large structures and cryo-EM maps. Has built-in AlphaFold fetch functionality and good PAE visualisation tools.
rbvi.ucsf.edu ↗iCn3D
NCBI's browser-based viewer. Good for aligning multiple structures and analysing sequences alongside structures.
ncbi.nlm.nih.gov ↗Common beginner mistakes to avoid
- Using the prediction without checking confidence first. Always look at pLDDT before analysing any structural feature. Orange regions are not reliable.
- Forgetting to check if an experimental structure already exists. Before running ColabFold for 30 minutes, check the PDB (rcsb.org) for your protein. An experimental structure is always preferable for high-stakes work.
- Ignoring the PAE for multi-domain proteins. Even if each domain looks blue, the relative orientation of domains may be uncertain. Always download and examine the PAE JSON for multi-domain predictions.
- Comparing AlphaFold structures to each other as if they're experimental. Two AlphaFold predictions for slightly different sequences will differ — but you can't be sure whether the differences are real structural differences or prediction artefacts.
- Not specifying the organism. If you search by protein name without specifying organism, you may get a bacterial or yeast version rather than the human one. Always confirm the UniProt accession before downloading.
- Submitting very long sequences to ColabFold without splitting into domains. Proteins >1,500 residues are slower and sometimes less accurate. Check if the protein has well-defined domains you can predict separately, then compare.
Key points from this chapter
- Always check the AlphaFold database first — most well-studied proteins are already there.
- Use UniProt to find the accession ID; prefer Swiss-Prot (reviewed) entries.
- ColabFold runs AlphaFold 2 on Google's free GPUs — no installation required, takes 15–60 min.
- AlphaFold Server (alphafoldserver.com) provides AlphaFold 3 predictions including complexes.
- Mol* and ChimeraX can colour structures by pLDDT — always do this before interpretation.
- Check PDB first for experimental structures; they beat AlphaFold predictions for critical work.