Extended Data Fig. 1: Detailed information regarding PTM site identification in PTMAtlas.

a Multi-step filtering process for PTM site identification, including dataset-specific PSM and site-level FDR control, cross-datasets site-level FDR control, and site localization probability filtering. Numbers in the parentheses represent corresponding protein numbers. b Distribution of modified amino acids for phosphorylation and methylation. c Substrate overlap for the four types of PTMs targeting lysine.