Fig. 3: fliX-MS of in vitro assembled human nucleosomes.
a fliX-MS revealed 12 unique peptide–nucleotide cross-links. The sequences of the cross-linked peptides are shown. For cross-links that could be located on one or several amino acids, the location within the peptide is marked in red letters. The cross-linked nucleotide sequence derived from precursor mass differences (A: deoxyadenosine, C: deoxycytidine, G: deoxyguanosine, T: thymidine), charge state, mass-to-charge ratio (m/z), and mass error (∆m) are shown. The cross-linked base is marked in red letters. b Base distribution among cross-links. c Crystal structure of the human recombinant nucleosome (PDB ID: 2CV58), with cross-linked amino acids marked in red (close to DNA) and orange (distant to DNA). For cross-links with more than one potential cross-linked amino acid, the residue closest to the DNA is marked.
