Multi-objective Genetic Programming with Multi-view Multi-level Feature for Enhanced Protein Secondary Structure Prediction
Organizations: National Frontiers Science Center for Industrial Intelligence and Systems Optimization, Shenyang 110819, China · Key Laboratory of Data Analytics and Optimization for Smart Industry (Northeastern University), Ministry of Education, Shenyang 110819, China · Liaoning Engineering Laboratory of Data Analytics and Optimization for Smart Industry, Shenyang 110819, China · Liaoning Key Laboratory of Manufacturing System and Logistics Optimization, Shenyang 110819, China ·
Abstract
Predicting protein secondary structure is essential for understanding protein function and advancing drug discovery. However, the intricate sequence-structure relationship poses significant challenges for accurate modeling. To address these, we propose MOGP-MMF, a multi-objective genetic programming framework that reformulates PSSP as an automated optimization task focused on feature selection and fusion. Specifically, MOGP-MMF introduces a multi-view multi-level representation strategy that integrates evolutionary, semantic, and newly introduced structural views to capture the comprehensive protein folding logic. Leveraging an enriched operator set, the framework evolves both linear and nonlinear fusion functions, effectively capturing high-order feature interactions while reducing fusion complexity. To resolve the accuracy-complexity trade-off, an improved multi-objective GP algorithm is developed, incorporating a knowledge transfer mechanism that utilizes prior evolutionary experience to guide the population toward global optima. Extensive experiments across seven benchmark datasets demonstrate that MOGP-MMF surpasses state-of-the-art methods, particularly in Q8 accuracy and structural integrity. Furthermore, MOGP-MMF generates a diverse set of non-dominated solutions, offering flexible model selection schemes for various practical application scenarios. The source code is available on GitHub: https://github.com/qian-ann/MOGP-MMF/tree/main.
Figures & tables
| Function | Type | Description |
|---|---|---|
| linear | Add two weighted features | |
| linear | Subtract two weighted features | |
| Mul | non-linear | Multiply filter |
| GRT | non-linear | Select maximum value between two features |
| Sqrt | non-linear | Sqrt an feature |
| Log | non-linear | Logarithm function |
| Constant | Type | Description |
|---|---|---|
| Integer | The parameters for the and functions. They are randomly generated in the range of [1,10). | |
| Integer | The convolution kernel size of is with values ranging from 1 to 4. | |
| Integer | The transform dimension for with possible values of 1. |
| Hyperparameter | Setting |
|---|---|
| Number of epochs | 100 |
| Dropout rate | 0.2 |
| Batch size | 64 |
| Maximum sequence length | 700 |
| Number of labels | 8 |
| Kernel size (CNNs) | 9 |
| Dataset | Method | Q8 | Precision | Recall | F1-score | MCC | Sov |
|---|---|---|---|---|---|---|---|
| CB6133 | NetSurfP-3.0 | 0.765 | 0.771 | 0.765 | 0.756 | 0.711 | 76.2 |
| AttSec | 0.783 | 0.774 | 0.783 | 0.773 | 0.730 | 78.9 | |
| Mufold-SS | 0.711 | 0.696 | 0.711 | 0.685 | 0.627 | 71.7 | |
| ShuffleNet_SS | 0.735 | 0.723 | 0.735 | 0.725 | 0.667 | 75.1 | |
| DeepACLSTM | 0.733 | 0.720 | 0.733 | 0.716 | 0.662 | 73.8 | |
| 2C-BLSTM | 0.735 | 0.720 | 0.735 | 0.721 | 0.665 | 73.8 |
| Method | Representation | CB6133 | CB6133 | CB513 | CASP10 | CASP11 | CASP12 | CASP13 | CASP14 |
| (Validation) | (Test) | ||||||||
| Single-view Single-level feature | HMM-CNN1 | 69.86 | 70.35 | 66.91 | 69.61 | 68.14 | 66.47 | 63.46 | 61.50 |
| HMM-CNN2 | 72.11 | 72.64 | 69.33 | 71.39 | 70.50 | 46.69 | 45.70 | 42.87 | |
| HMM-RNN1 | 72.58 | 72.99 | 69.56 | 70.95 | 70.59 | 69.19 | 66.80 | 65.33 | |
| HMM-RNN2 | 72.46 | 72.91 | 69.37 | 71.84 | 70.54 | 69.68 | 66.29 | 65.81 | |
| PSSM-CNN1 | 69.44 | 69.58 | 66.33 | 68.91 | 66.24 | 59.70 | 58.63 | 59.53 |
| Method | CB6133 | CB6133 | CB513 | CASP10 | CASP11 | CASP12 | CASP13 | CASP14 |
|---|---|---|---|---|---|---|---|---|
| (Validation) | (Test) | |||||||
| Add | 78.00 | 78.47 | 74.89 | 78.55 | 75.85 | 73.60 | 71.39 | 68.35 |
| Mul | 54.61 | 55.75 | 50.70 | 52.11 | 54.50 | 50.51 | 47.49 | 47.41 |
| Max | 77.97 | 78.25 | 74.75 | 78.55 | 75.62 | 72.08 | 69.59 | 67.79 |
| Min | 74.00 | 74.17 | 71.09 | 74.30 | 71.98 | 70.25 | 68.46 | 66.32 |
| Concatenation | 74.88 | 75.38 | 71.97 | 75.62 | 73.34 | 70.74 | 67.44 | 66.59 |
| Method | Anchor | Complexity | CB6133 (Test) | CB513 | CASP10 | CASP11 | CASP12 | CASP13 | CASP14 |
|---|---|---|---|---|---|---|---|---|---|
| Tree 1 | Low-Complexity | 15 | 79.39 | 75.98 | 79.76 | 76.41 | 68.28 | 66.15 | 62.70 |
| Tree 2 | Balanced | 28 | 79.91 | 76.89 | 80.32 | 77.26 | 73.16 | 71.19 | 67.50 |
| Tree 3 | High-Performance | 42 | 80.05 | 76.93 | 80.47 | 77.59 | 74.63 | 72.09 | 69.07 |