Data-Scarce, Multi-Granular, Multimodal: Benchmark Design for Biosynthetic Gene Clusters
Organizations: Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom · Department of Computer Science, The University of Manchester, Manchester, United Kingdom · Department of Chemistry, The University of Manchester, Manchester, United Kingdom · Division of Evolution, Infection and Genomics, The University of Manchester, Manchester, United Kingdom ·
Abstract
Biosynthetic gene clusters (BGCs) are co-located genes that encode the biosynthesis of specialized metabolites, an important source of antibiotics, anticancer agents, immunosuppressants, and agricultural bioactives. Deep learning, particularly self-supervised foundation models, has spurred interest in BGC sequence modeling, but evaluation has lagged behind: existing benchmarks often rely on coarse classification over small curated datasets, providing limited discrimination among models and insight into downstream utility. We propose a benchmark-design framework in which an informative benchmark should be discriminative, separating models with statistical confidence, and applicable, spanning scientifically meaningful tasks under different levels of generalization. We instantiate this framework as BGC-Bench, which derives five tasks from MIBiG, ranging from A-domain substrate prediction to BGC-molecule retrieval, evaluates them under genotype- and phenotype-shift splits, includes an active-learning setting for label-scarce discovery, and is easily extensible to new tasks and encoders. BGCs further provide a shared testbed across granularities and modalities: BGC-Bench compares twelve encoders on nucleotide, amino-acid, or Pfam-domain sequences, including compositional baselines for each input type, and combines BGC and chemical encoders for cross-modal retrieval. No single representation dominates: the best granularity depends on the biological scale of the task, and pretrained encoders do not consistently outperform other representations across tasks and splits. Active-learning experiments show that most tasks remain data-limited, encoder rankings change with labeling budget, and acquisition strategies yield modest gains. These results show that BGC model evaluation requires task-diverse, shift-aware benchmarks, and the framework can be generalized to benchmark design beyond BGCs.
Figures & tables
| Model | Dim. | Params | Representation details |
|---|---|---|---|
| Pfam-domain encoders | |||
| Bag-of-Pfam | 3,932 | – | Pfam-domain count vector, normalized |
| Random-Pfam | 256 | – | Random per-Pfam-token vectors, normalized after pooling |
| BiGCARP [ 20 ] | 256 | 34 M | ByteNet MLM on antiSMASH-DB [ 44 ] BGCs |
| Kawano [ 21 ] | 1,024 | 110 M | RoBERTa MLM on antiSMASH-DB bacterial BGCs |
| DeepBGC [ 22 ] | 256 | 1.6 M | Frozen Pfam2vec + BiLSTM; BGC-detection pretraining |
| Model | Coarse classes | Fine classes | Chem. properties | BGC–molecule retrieval | A-domain substrate | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| macro-AUROC | weighted macro-AUROC | mean Spearman | class-macro R@10 | top-1 accuracy | |||||||||||
| R | S | G | R | S | G | R | S | G | R | S | G | C | CV | G | |
| Pfam-domain encoders | |||||||||||||||
| Bag-of-Pfam | .929 | .877 | .884 | .880 | .825 | .753 | .354 | .281 | .283 | .624 | .546 | .495 | .275 | .196 | .151 |
| .020 | .042 | .029 | .031 | .028 | .041 | .057 | .057 | .054 | .062 | .109 | .081 | .039 | .018 | .043 | |
| Random-Pfam | .936 | .909 | .896 | .880 | .851 | .786 | .523 | .467 | .417 | .542 | .504 | .448 | .209 | – | – |
| Generalization splits | ||||
|---|---|---|---|---|
| Domain | Genotype side | Phenotype side | Functionality | Benchmarks |
| Small-molecule drug discovery | Scaffold, similarity-thresholded | Assay, target family | Property prediction, ADMET prediction, compound–target retrieval, hit identification, lead optimization | MoleculeNet [ 40 ] Lo-Hi [ 41 ] |
| Protein sequence modeling | Sequence identity, family/superfamily, mutation distance | Function class, substrate/binding, condition | Function annotation, fitness prediction, binding retrieval, protein engineering | TAPE [ 36 ] FLIP [ 38 ] PEER [ 37 ] ProteinGym [ 39 ] |
| MS/MS metabolomics | Scaffold, MCES distance, structure similarity | Spectral similarity, instrument, adduct, collision energy | Formula prediction, molecule retrieval, de novo structure generation | MassSpecGym [ 42 ] |
Appendix figures & tables21 assets
Supplementary material from the paper’s appendix.
Appendix
| Random | ||||||||
|---|---|---|---|---|---|---|---|---|
| NN distance | 0.514 | 0.529 | 0.560 | 0.580 | 0.590 | 0.570 | 0.576 | 0.460 |
| AUROC, BiG-SCAPE | 0.804 | 0.774 | 0.764 | 0.764 | 0.729 | 0.724 | 0.730 | 0.840 |
| AUROC, Pfam Jaccard | 0.831 | 0.787 | 0.777 | 0.752 | 0.742 | 0.765 | 0.745 | 0.862 |
| Grouping | Groups | ARI | within | vs. benchmark |
|---|---|---|---|---|
| Genotype ( BGCs) | ||||
| BiG-SCAPE families, (benchmark) | 416 | – | 0.806 | – |
| Pfam-domain Jaccard + Butina | 414 | 0.027 | 0.576 | 0.710 |
| Phenotype ( BGCs) | ||||
| Bemis–Murcko scaffold (benchmark) | 1,105 | – | 0.830 | – |
| Generic Murcko scaffold | 972 | 0.620 | 0.824 | 0.824 |
| Split | Train | Test | Targets |
|---|---|---|---|
| Coarse classes : BGCs; MIBiG classes, multi-label; macro-AUROC | |||
| Random | 1,949 | 488 | 6 |
| Scaffold | 1,570 | 374 | 6 |
| GCF ( ) | 2,057 | 376 | 6 |
| Fine classes : BGCs; NPClassifier classes, multi-label; weighted macro-AUROC | |||
| Random (fold 4) | 980 | 241 | 48 |
| Descriptor | Group | Source |
|---|---|---|
| MolWt | ADMET | Lipinski; GuacaMol |
| MolLogP | ADMET | Lipinski; GuacaMol |
| NumHDonors | ADMET | Lipinski; GuacaMol |
| NumHAcceptors | ADMET | Lipinski; GuacaMol |
| TPSA | ADMET | Veber; GuacaMol |
| NumRotatableBonds | ADMET | Veber; GuacaMol |
| Literature panel (13) | Data-driven panel (66) | |||||
| Encoder | Rand. | Scaf. | GCF | Rand. | Scaf. | GCF |
| Pfam-domain encoders | ||||||
| Bag-of-Pfam | 0.354 | 0.281 | 0.283 | 0.277 | 0.198 | 0.155 |
| Random-Pfam | 0.523 | 0.467 | 0.417 | 0.406 | 0.347 | 0.303 |
| BiGCARP | 0.574 | 0.519 | 0.509 | 0.430 | 0.370 | 0.340 |
| Kawano | 0.455 | 0.345 | 0.337 | 0.309 | 0.227 | 0.217 |
| Setting | Value |
|---|---|
| Shared dimension | |
| Optimizer | AdamW |
| Learning rate | |
| Weight decay | |
| Batch size | BGC–product pairs |
| Temperature | Learnable; initialized at , minimum |
| Features | 5-fold (BGC-grouped) | GCF holdout |
|---|---|---|
| Stachelhaus code (9 residues) | 0.830 [0.814, 0.846] | 0.825 [0.781, 0.866] |
| Amino-acid 3-mer (best encoder in Table 2 ) | 0.781 [0.764, 0.799] | 0.747 [0.695, 0.791] |
| Majority substrate | 0.106 | 0.127 |
| Encoder | Backbone | Pretraining corpus | Vocabulary | Objective | Downstream pooling |
|---|---|---|---|---|---|
| Bag-of-Pfam | none (compositional baseline) | no pretraining; raw Pfam-domain bag-of-counts representation | Pfam IDs | none | per-BGC Pfam-domain count vector, -normalized ( -dim) |
| Random-Pfam | none (compositional baseline) | no pretraining; one fixed random vector per Pfam ID | Pfam IDs | none | i.i.d. vector per Pfam ID (seed 42), averaged over the cluster’s Pfam tokens, -normalized ( -dim) |
| BiGCARP [ 20 ] | ByteNet, layers, , M params | antiSMASH-DB [ 44 ] BGC Pfam-domain sequences ( BGCs before train/validation/test split) | tokens | masked-token prediction (MLM) | mean of last-layer token states across the Pfam sequence ( -dim) |
| BiGCARP-CLS [ 20 ] (ablation) | same as BiGCARP | same as BiGCARP | same as BiGCARP | same as BiGCARP | last-layer state of a mask token prepended at position 0 ( -dim) |
| Kawano [ 21 ] | RoBERTa, layers, heads, hidden ( 110 M params) | antiSMASH-DB bacterial BGC Pfam-domain sequences ( BGCs; Model I of four released models) | -token vocabulary | masked-token prediction (MLM) | mean of last-layer hidden states across the Pfam sequence, ( -dim) |
| DeepBGC [ 22 ] | Pfam2vec ( -dim) + BiLSTM ( units, bidirectional) | Pfam-domain sequences of bacterial genomes (Pfam2vec); MIBiG 1.4 BGCs ( accessions) and synthetic negatives (BiLSTM; released v0.1.0 detector) | Pfam IDs | supervised binary BGC detection | cluster boundary flags as input; mean last-layer BiLSTM states ( -dim) |
| Task or setting | Configuration |
|---|---|
| Linear probes | |
| Multi-label classification | One-vs-rest logistic regression |
| A-domain substrates | Multinomial logistic regression |
| Logistic regression settings | L 2 penalty; ; maximum iterations |
| Chemical properties | Ridge regression; |
| MLP classification and regression | |
| (a) Classification and chemical properties | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Model | Coarse classes | Fine classes | Chem. properties | ||||||
| macro-AUROC | weighted macro-AUROC | mean Spearman | |||||||
| Rand. | Scaf. | GCF | Rand. | Scaf. | GCF | Rand. | Scaf. | GCF | |
| Pfam-domain encoders | |||||||||
| Bag-of-Pfam | |||||||||
| Random-Pfam | |||||||||
| Encoder | PKS | NRPS | Ribosomal (RiPP) | Terpene | Saccharide | Other |
|---|---|---|---|---|---|---|
| Pfam-domain encoders | ||||||
| Bag-of-Pfam | 0.950 | 0.941 | 0.997 | 0.942 | 0.868 | 0.873 |
| Random-Pfam | 0.962 | 0.952 | 0.992 | 0.963 | 0.892 | 0.856 |
| BiGCARP | 0.973 | 0.961 | 0.980 | 0.969 | 0.935 | 0.896 |
| BiGCARP-CLS | 0.954 | 0.933 | 0.993 | 0.937 | 0.912 | 0.842 |
| Kawano | 0.966 | 0.965 | 0.966 | 0.957 | 0.921 | 0.833 |
| Encoder | Mean split-CI bounds | |
|---|---|---|
| DeepBGC | 0.546 | [0.499, 0.587] |
| BiGCARP | 0.535 | [0.485, 0.580] |
| Random-Pfam | 0.469 | [0.415, 0.515] |
| BGC-Prophet | 0.452 | [0.401, 0.499] |
| BiGCARP-CLS | 0.442 | [0.392, 0.484] |
| Amino-acid 3-mer | 0.431 | [0.375, 0.482] |
| B C | C B | |||||||
| Encoder | Rand. | Scaf. | GCF | Class | Rand. | Scaf. | GCF | Class |
| Pfam-domain encoders | ||||||||
| Bag-of-Pfam | 0.624 0.006 | 0.546 0.021 | 0.495 0.019 | 0.275 0.012 | 0.633 0.009 | 0.607 0.029 | 0.493 0.013 | 0.286 0.007 |
| Random-Pfam | 0.542 0.005 | 0.504 0.041 | 0.448 0.032 | 0.209 0.006 | 0.553 0.003 | 0.544 0.043 | 0.466 0.022 | 0.288 0.015 |
| BiGCARP | 0.559 0.004 | 0.466 0.037 | 0.435 0.020 | 0.222 0.007 | 0.556 0.005 | 0.503 0.011 | 0.470 0.021 | 0.256 0.002 |
| BiGCARP-CLS | 0.372 0.024 | 0.291 0.024 | 0.248 0.020 | 0.119 0.005 | 0.373 0.031 | 0.429 0.021 | 0.263 0.024 | 0.140 0.004 |
| Coarse classes (macro-AUROC) | Fine classes (weighted macro-AUROC) | Chem. prop. (mean Spearman ) | |||||||
| Encoder | Random | Scaffold | GCF | Random | Scaffold | GCF | Random | Scaffold | GCF |
| Pfam-domain encoders | |||||||||
| Bag-of-Pfam | 0.950 | 0.896 | 0.891 | 0.886 | 0.859 | 0.778 | 0.585 | 0.523 | 0.469 |
| Random-Pfam | 0.957 | 0.957 | 0.929 | 0.905 | 0.899 | 0.828 | 0.655 | 0.560 | 0.529 |
| BiGCARP | 0.970 | 0.950 | 0.943 | 0.912 | 0.893 | 0.847 | 0.678 | 0.604 | 0.568 |
| BiGCARP-CLS | 0.951 | 0.933 | 0.931 | 0.876 | 0.840 | 0.832 | 0.574 | 0.479 | 0.523 |
| Retrieval (class-macro R@10) | A-domain substrate (top-1) | |||||
| Encoder | Random | Scaffold | GCF | Class | 5-fold | GCF |
| Pfam-domain encoders | ||||||
| Bag-of-Pfam | 0.631 | 0.582 | 0.502 | 0.249 | 0.198 | 0.137 |
| Random-Pfam | 0.580 | 0.540 | 0.442 | 0.219 | – | – |
| BiGCARP | 0.595 | 0.529 | 0.460 | 0.232 | 0.277 ↑ | 0.168 |
| BiGCARP-CLS | 0.385 | 0.328 | 0.252 | 0.135 | – | – |
| Model | Coarse classes | Fine classes | Chem. properties | BGC–molecule retrieval | A-domain substrate | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| macro-AUROC | weighted macro-AUROC | mean Spearman | class-macro R@10 | top-1 accuracy | |||||||||||
| R | S | G | R | S | G | R | S | G | R | S | G | C | CV | G | |
| Pfam-domain encoders | |||||||||||||||
| Bag-of-Pfam | .954 | .938 | .920 | .886 | .846 | .789 | .622 ↑ | .595 ↑ | .525 ↑ | .596 | .551 | .532 | .247 | .194 | .106 |
| Kawano | .929 | .915 | .885 | .837 | .804 | .787 | .565 ↑ | .501 ↑ | .474 ↑ | .512 | .457 | .413 | .177 | .200 | .106 |
| Amino-acid encoders | |||||||||||||||
| BiGCARP | Kawano | ||||||
|---|---|---|---|---|---|---|---|
| Task | Probe | Rand. | Scaf. | GCF | Rand. | Scaf. | GCF |
| Coarse classes | linear | ||||||
| MLP | |||||||
| Fine classes | linear | ||||||
| MLP | |||||||
| Chem. properties | linear | ||||||
| TypiClust random | BADGE random | ||||||||
| Encoder | Coarse | Fine | Chem. | Retr. | A-dom. | Coarse | Fine | Retr. | A-dom. |
| Bag-of-Pfam | +0.5 | +0.8 | 1.6 | +0.3 | +0.8 | +2.6 | +0.1 | +2.3 | 0.0 |
| Random-Pfam | +3.0 | +0.7 | +4.0 | +5.5 | – | +0.9 | 0.2 | +1.4 | – |
| BiGCARP | +1.1 | +1.5 | +6.8 | +5.3 | +1.5 | +1.6 | 0.4 | +1.3 | 0.0 |
| Kawano | +3.0 | +1.5 | +3.7 | +5.9 | +1.2 | +1.3 | 0.5 | +0.8 | +0.1 |
| DeepBGC | +1.7 | +1.5 | +1.5 | +3.2 | – | +1.1 | +0.8 | +0.5 | – |
| Encoder | Coarse | Fine | Chem. | Retr. | A-dom. |
|---|---|---|---|---|---|
| Bag-of-Pfam | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 |
| Random-Pfam | 1.57 | 1.13 | 0.28 | 0.83 | – |
| BiGCARP | 2.22 | 1.12 | 1.00 | 1.18 | 0.91 |
| Kawano | 1.72 | 1.01 | 0.60 | 0.78 | 1.19 |
| DeepBGC | 1.49 | 0.86 | 1.26 | 0.58 | – |
| Amino-acid 3-mer | 0.27 | 0.81 | 0.63 | 0.53 | 4.00 |
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Benchmark design creates tasks, datasets, metrics, and protocols that make AI capabilities measurable and comparisons credible.
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