National Center for
3MCE: Crystal structure of the NAC domain of alpha subunit of nascent polypeptide-associated complex(NAC)
Crystal structures of NAC domains of human nascent polypeptide-associated complex (NAC) and its alphaNAC subunit
Protein Cell (2010) 1 p.406-416
Nascent polypeptide associated complex (NAC) and its two isolated subunits, alphaNAC and betaNAC, play important roles in nascent peptide targeting. We determined a 1.9 A resolution crystal structure of the interaction core of NAC heterodimer and a 2.4 A resolution crystal structure of alphaNAC NAC domain homodimer. These structures provide detailed information of NAC heterodimerization and alphaNAC homodimerization. We found that the NAC domains of alphaNAC and betaNAC share very similar folding despite of their relative low identity of amino acid sequences. Furthermore, different electric charge distributions of the two subunits at the NAC interface provide an explanation to the observation that the heterodimer of NAC complex is more stable than the single subunit homodimer. In addition, we successfully built a betaNAC NAC domain homodimer model based on homologous modeling, suggesting that NAC domain dimerization is a general property of the NAC family. These 3D structures allow further studies on structure-function relationship of NAC.