Structure alignment
Superpose two structures and score how similar their folds are, with TM-score.
First structure
Or drop a file here.
Second structure
Or drop a file here.
Load two structures to align them. Files are read in your browser and neither is uploaded.
TM-score = (1/L) Σ 1/(1 + (dᵢ/d₀)²); d₀ = 1.24·∛(L−15) − 1.8- TM-align, the structural alignment algorithm implemented here — Nucleic Acids Research, 2005
- TM-score and the d0 length normalisation — Proteins: Structure, Function, and Bioinformatics, 2004
- Closed-form optimal superposition of two point sets — Acta Crystallographica Section A, 1976
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TM-score is asymmetric — it depends which length you divide by — so both are shown rather than one being chosen for you. Above about 0.5 two structures share a fold; below about 0.3 they are no more alike than two proteins picked at random. Only alpha carbons are used. This is an independent implementation of the published method and will not agree with the reference program to the third decimal.
About this tool
Load two PDB or mmCIF files and align them by geometry alone, without needing their sequences to match. Reports TM-score under both normalisations, RMSD over the aligned residues, the alignment itself and where the two structures diverge. Both files are read in your browser and neither is uploaded.
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Science last reviewed .