COMMD is a new family of proteins with homology to MURR1, a multifunctional protein that inhibits NFkB. These proteins form multimeric complexes and were identified in a biochemical screen for MURR1-associated factors. The family is defined by the presence of a conserved and unique motif termed the COMM (copper metabolism gene MURR1) domain, which functions as an interface for protein-protein interactions. The prototype of this family, MURR1/COMMD1, suppresses NFkB by affecting the association of NF-kappaB with chromatin. COMMD7 (COMM domain-containing protein 7) interacts with COMMD1 via its COMM domain. It also associates with the NF-kappa-B complex and suppresses its transcriptional activity.