The COP9 signalosome (CSN) is an evolutionarily conserved protein complex that functions as a deneddylase to inactivate Cullin-RING E3 ligases for controlling protein ubiquitination. CSN possesses structural flexibility that is important for its activation upon binding to a diverse array of CRLs. The canonical and non-canonical CSN complexes consist of 8 (CSN1-8) and 9 (CSN1-9) subunits, respectively. Although CSN9 is not essential for CSN assembly and function, it appears to be important in non-catalytic regulation of CRLs by CSN. Here we employed a combinatory cross-linking mass spectrometry (XL-MS) approach to generate the largest PPI maps of human CSN complexes, which significantly enhanced the precision of integrative structural modeling. The resulting integrative structures allowed us not only to elucidate architectures of both complexes, but also to assess CSN structural dynamics that was not described in the crystal structure. In addition, we have determined CSN9 docking sites and its impact on the CSN structure. While CSN9 binding did not induce global conformational changes, it triggered subunit local reorientations that may be associated with CSN9 involvement in CSN-mediated steric regulation of CRLs.