CDC48 N-terminal domain
{{Short description|Protein domain}}
{{Infobox protein family
| Symbol = CDC48_N
| Name = CDC48_N
| image = PDB 1s3s EBI.jpg
| width =
| caption = crystal structure of aaa atpase p97/vcp nd1 in complex with p47 c
| Pfam = PF02359
| Pfam_clan =
| InterPro = IPR003338
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1cz4
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}
{{Infobox protein family
| Symbol = CDC48_2
| Name = CDC48_2
| image = PDB 1qdn EBI.jpg
| width =
| caption = amino terminal domain of the n-ethylmaleimide sensitive fusion protein (nsf)
| Pfam = PF02933
| Pfam_clan = CL0402
| InterPro = IPR004201
| SMART =
| PROSITE =
| MEROPS =
| SCOP = 1cz4
| TCDB =
| OPM family =
| OPM protein =
| CAZy =
| CDD =
}}
In molecular biology, the CDC48 N-terminal domain is a protein domain found in AAA ATPases including cell division protein 48 (CDC48), VCP-like ATPase and N-ethylmaleimide sensitive fusion protein. It is a substrate recognition domain which binds polypeptides, prevents protein aggregation, and catalyses refolding of permissive substrates. It is composed of two equally sized subdomains. The amino-terminal subdomain (CDC48_N) forms a double-psi beta-barrel whose pseudo-twofold symmetry is mirrored by an internal sequence repeat of 42 residues. The carboxy-terminal subdomain (CDC48_2) forms a novel six-stranded beta-clam fold.{{cite journal |vauthors=Coles M, Diercks T, Liermann J, Groger A, Rockel B, Baumeister W, Koretke KK, Lupas A, Peters J, Kessler H | title = The solution structure of VAT-N reveals a 'missing link' in the evolution of complex enzymes from a simple betaalphabetabeta element | journal = Curr. Biol. | volume = 9 | issue = 20 | pages = 1158–68 |date=October 1999 | pmid = 10531028 | doi = 10.1016/S0960-9822(00)80017-2 | s2cid = 6561497 | doi-access = free }} Together these subdomains form a kidney-shaped structure, in close agreement with results from electron microscopy. CDC48_N is related to numerous proteins including prokaryotic transcription factors, metabolic enzymes, the protease cofactors UFD1 and PrlF, and aspartic proteinases.