Xu, G.; Yang, Y.; Lv, Y.; Luo, Z.; Wang, Q.; Ma, J.

Protein B-factor, also known as the Debye-Waller factor, measures the fluctuation of an atom around its average position. It serves as a crucial indicator of protein flexibility and dynamics. However, accurately predicting the B-factor of C alpha atoms remains challenging. In this work, we introduce OPUS-BFactor, a tool for predicting the normalized protein B-factor. OPUS-BFactor operates in two modes: the first mode, OPUS-BFactor-seq, uses sequence information as input, allowing predictions based solely on protein sequence; the second mode, OPUS-BFactor-struct, uses structural information, requiring the 3D structure of the target protein. Evaluation on three test sets, including recently released targets from CAMEO and CASP15, demonstrates that OPUS-BFactor significantly outperforms other B-factor prediction methods. Therefore, OPUS-BFactor is a valuable tool for predicting protein properties related to the B-factor, such as flexibility, thermal stability, and region activity.