> ## Documentation Index > Fetch the complete documentation index at: https://proto.evodesign.org/docs/llms.txt > Use this file to discover all available pages before exploring further. # Structure pTM Score > Evaluate structure quality using predicted TM score
Structure pTM Score
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Structure Prediction ยท 7 tools
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evo-design/proto-language/proto\_language/constraint/protein\_structure/structure\_confidence\_constraint.py
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Evaluate structure quality using predicted TM-score (pTM). pTM (predicted Template Modeling score) measures overall structural accuracy of the predicted model. Values range from 0.0 to 1.0, where higher values indicate better global fold quality. This constraint returns `1.0 - ptm`, so lower scores indicate better predicted structure quality. **Supported tools**: ESMFold, ESMFold2, AlphaFold3, Boltz2, Chai1, Protenix, AlphaFold2, AlphaFold2 binder ## API Reference
ConfigStructureBasedConstraintConfig Source
Base configuration for constraints using structure prediction tools. This base class standardizes how structure prediction tools and their configurations are specified across all structure-based constraints. Each tool has its own dedicated config field. Subclasses can optionally restrict which tools are supported by overriding the structure\_tool field with a narrower Literal type. Predictor: esmfold/esmfold2/alphafold3/boltz2/chai1/protenix/alphafold2/alphafold2\_binder. Options: `esmfold`, `esmfold2`, `alphafold3`, `boltz2`, `chai1`, `protenix`, `alphafold2`, `alphafold2_binder` Configuration for ESMFold structure prediction. Configuration for ESMFold2 structure prediction. Configuration for AlphaFold3 structure prediction. Configuration for Boltz2 structure prediction. Configuration for Chai1 structure prediction. Configuration for Protenix structure prediction. Configuration for the general AlphaFold2 multimer structure predictor. Configuration for the AF2 binder-design backend.
ReturnsConstraintOutput
Per-proposal score and `ptm` / `pdb_output` / `structure_tool` metadata; predicted Structure attaches to slot 0.
## Usage Programming a homo-dimer with ESMFold: ```python python icon="python" theme={null} >>> from proto_language.core import Segment >>> protomer = Segment(length=20, sequence_type="protein") >>> esmfold_plddt = Constraint( ... inputs=[protomer, protomer], ... function=structure_ptm_constraint, ... function_config={"structure_tool": "esmfold"}, ... ) ``` ## Metadata | Property | Value | | --------------- | --------------------------------- | | Key | `structure-ptm` | | Function | `structure_ptm_constraint` | | Category | `protein_structure` | | Mode | `discrete` | | Uses GPU | `True` | | Supported Types | `protein`, `rna`, `dna`, `ligand` |