The human proteome with direct physical access to DNA

Highlights • High-yield protein-DNA photo-crosslinking via metabolic labeling and UV-LED irradiation • Widespread and extensive intrinsic disorder among proteins with physical access to DNA • DNA-crosslinked peptides map in vivo DNA interactions with single-amino-acid resolution • Differential quantification of DNA-bound transcription factors and chromatin organizers Summary In a human cell, DNA is packed with histones, RNA, and chromatin-associated proteins, forming a cohesive gel. At any given moment, only a subset of the proteome has physical access to the DNA and organizes its structure, transcription, replication, repair, and other essential molecular functions. We have developed a “zero-distance” photo-crosslinking approach to quantify proteins in direct contact with DNA in living cells. Collecting DNA interactomes from human breast cancer cells, we present an atlas of over one thousand proteins with physical access to DNA and hundreds of peptide-nucleotide crosslinks pinpointing protein-DNA interfaces with single-amino-acid resolution. Quantitative comparisons of DNA interactomes from differentially treated cells recapitulate the recruitment of key transcription factors as well as DNA repair proteins and uncover fast-acting restrictors of chromatin accessibility on a timescale of minutes. This opens a direct way to explore genomic regulation in a hypothesis-free manner, applicable to many organisms and systems.     «

Highlights • High-yield protein-DNA photo-crosslinking via metabolic labeling and UV-LED irradiation • Widespread and extensive intrinsic disorder among proteins with physical access to DNA • DNA-crosslinked peptides map in vivo DNA interactions with single-amino-acid resolution • Differential quantification of DNA-bound transcription factors and chromatin organizers Summary In a human cell, DNA is packed with histones, RNA, and chromatin-associated proteins, forming a cohesive gel...     »