Updated publication reference for PubMed record(s): 34929720. Chemical cross-linking coupled to mass spectrometry was used to study the subunit organization of the NALCN channelosome consisting of the proteins NALCN, FAM155A, UNC79 and UNC80. Cross-linking data was generated using the reagents disuccinimidyl suberate (DSS), pimelic dihydrazide (PDH), and 4-(4,6-Dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium (DMTMM) chloride, and was analyzed in combination with data from cryo-electron microscopy.