“…The first feature set contains 526 feature channels: one-hot-encoder of the target sequence (1D features, 20*2 channels); position-specific frequency matrix (1D features, 21*2 channels, considering gap) and positional entropy ( Yang et al, 2020 ) (1D features, 1*2 channels); and coupling features ( Yang et al, 2020 ) (2D features, 441 channels) derived from the inverse of the shrunk covariance matrix of MSA. The second feature set contains 151 feature channels: one-hot-encoder of the target sequence (1D features, 20*2 channels), position-specific scoring matrix ( Altschul et al, 1997 ) (1D features; 20*2 channels; not considering gap), HMM profile ( Remmert et al, 2012 ) (1D features, 30*2 channels), secondary structure from SPOT-1D (Hanson et al, 2019) (1D features, 3*2 channels), solvent accessible surface area from SPOT-1D ( Hanson et al, 2019 ) (1D features, 1*2 channels), CCMPRED score (Seemayer et al, 2014) (2D features, 1 channel), mutual information ( Zhang et al, 2022 ) (2D feature, 1 channel), and statistical pair-wise contact potential ( Betancourt and Thirumalai, 1999 ) (2D feature, 1 channel). The first feature set, indicated as FeatSet1, is mainly composed of 2D direct coupling features (441 out of 526 total features) from the MSA, while the second feature set, indicated as FeatSet2, is mainly composed of 1D sequence-based features (148 out of 151 total features).…”