Enhancing Protein Structure Learning using a Size-Guided Conditional Mixture-of-Experts

In recent years, deep learning on protein structures has attracted widespread attention, as structures determine proteins' function. A series of structure-based protein property prediction methods have been proposed, achieving remarkable performance. However, these methods often neglect the importance of the protein size and fail to fully leverage it, leading to biases toward certain sizes and suboptimal overall performance. To address this issue, we propose a protein size-guided conditional mixture-of-experts for improving deep learning on protein structures. It can adaptively activate the sub-networks with the guidance of protein sizes and network features. Its flexible combinations of sub-networks help mitigate biases toward certain protein sizes, while the deliberate incorporation of protein size guidance enables the network to effectively capture both universal and size-specific characteristics, resulting in more accurate predictive performance. Based on it, we propose a framework for protein property prediction and benchmark it on eight tasks with two representation forms of proteins and three different dataset splits, a total of forty-eight tests. Experiments show that our method can be seamlessly integrated into numerous existing models and achieve performance improvement across tasks under almost all settings. More importantly, our experiments reveal that although often overlooked, protein size serves as an important prior knowledge in deep learning on protein structures.