6oaa | pdb_00006oaa

Cdc48-Npl4 complex processing poly-ubiquitinated substrate in the presence of ADP-BeFx, state 1

Loading... Status: waiting for Mol* initialization Structural highlights 6oaa is a 6 chain structure with sequence from Atcc 18824. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: ADP, BEF Gene: CDC48, YDL126C (ATCC 18824), NPL4, HRD4, YBR170C, YBR1231 (ATCC 18824), RPL40A, UBI1, YIL148W (ATCC 18824) Activity: Vesicle-fusing ATPase, with EC number 3.6.4.6 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [CDC48_YEAST] ATP-dependent chaperone which probably uses the energy provided by ATP hydrolysis to generate mechanical force to unfold substrate proteins, disassemble protein complexes, and disaggregate protein aggregates (PubMed:21454554). By recruiting and promoting the degradation of ubiquitinated proteins, plays a role in the ubiquitin fusion degradation (UFD) pathway (PubMed:16428438). Has a role in the endoplasmic reticulum-associated degradation (ERAD) pathway which mediates the cytoplasmic elimination of misfolded proteins exported from the ER (PubMed:11813000, PubMed:11740563, PubMed:11847109, PubMed:21148305). Required for the proteasome-dependent processing/activation of MGA2 and SPT23 transcription factors leading to the subsequent expression of OLE1 (PubMed:11847109, PubMed:11733065). Has an additional role in the turnover of OLE1 where it targets ubiquitinated OLE1 and other proteins to the ERAD (PubMed:11847109). Regulates ubiquitin-mediated mitochondria protein degradation (PubMed:21070972, PubMed:27044889). Involved in spindle disassembly probably by promoting the degradation of spindle assembly factors ASE1 and CDC5 at the end of mitosis (PubMed:14636562). Component of the ribosome quality control complex (RQC), a ribosome-associated complex that mediates ubiquitination and extraction of incompletely synthesized nascent chains for proteasomal degradation (PubMed:23178123, PubMed:24261871). CDC48 may provide the mechanical force that dislodges the polyubiquitinated nascent peptides from the exit channel (PubMed:23178123, PubMed:24261871). Required for ribophagy, a process which relocalizes ribosomal particles into the vacuole for degradation in response to starvation (PubMed:20508643). [RL40A_YEAST] Ubiquitin: Exists either covalently attached to another protein, or free (unanchored). When covalently bound, it is conjugated to target proteins via an isopeptide bond either as a monomer (monoubiquitin), a polymer linked via different Lys residues of the ubiquitin (polyubiquitin chains) or a linear polymer linked via the initiator Met of the ubiquitin (linear polyubiquitin chains). Polyubiquitin chains, when attached to a target protein, have different functions depending on the Lys residue of the ubiquitin that is linked: Lys-6-linked may be involved in DNA repair; Lys-11-linked is involved in ERAD (endoplasmic reticulum-associated degradation) and in cell-cycle regulation; Lys-29-linked is involved in lysosomal degradation; Lys-33-linked is involved in kinase modification; Lys-48-linked is involved in protein degradation via the proteasome; Lys-63-linked is involved in endocytosis, and DNA-damage responses. Linear polymer chains formed via attachment by the initiator Met lead to cell signaling. Ubiquitin is usually conjugated to Lys residues of target proteins, however, in rare cases, conjugation to Cys or Ser residues has been observed. When polyubiquitin is free (unanchored-polyubiquitin), it also has distinct roles, such as in activation of protein kinases, and in signaling (By similarity). 60S ribosomal protein L40-A: Component of the ribosome, a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell. The small ribosomal subunit (SSU) binds messenger RNAs (mRNAs) and translates the encoded message by selecting cognate aminoacyl-transfer RNA (tRNA) molecules. The large subunit (LSU) contains the ribosomal catalytic site termed the peptidyl transferase center (PTC), which catalyzes the formation of peptide bonds, thereby polymerizing the amino acids delivered by tRNAs into a polypeptide chain. The nascent polypeptides leave the ribosome through a tunnel in the LSU and interact with protein factors that function in enzymatic processing, targeting, and the membrane insertion of nascent chains at the exit of the ribosomal tunnel (PubMed:22096102). eL40 is essential for translation of a subset of cellular transcripts, including stress response transcripts, such as DDR2 (PubMed:23169626). [NPL4_YEAST] Involved in the import of nuclear-targeted proteins into the nucleus and the export of poly(A) RNA out of the nucleus (PubMed:8930904, PubMed:11733065). Has a role in the endoplasmic reticulum-associated degradation (ERAD) pathway (PubMed:11739805, PubMed:11740563, PubMed:11847109). Required for the proteasome-dependent processing/activation of MGA2 and SPT23 transcription factors leading to the subsequent expression of OLE1 (PubMed:11733065). Has an additional role in the turnover of OLE1 where it targets ubiquitinated OLE1 and other proteins to the ERAD (PubMed:11847109). Regulates ubiquitin-mediated mitochondria protein degradation (PubMed:21070972). Involved in spindle disassembly probably by promoting the degradation of spindle assemby factors ASE1 and CDC5 at the end of mitosis (PubMed:14636562). Publication Abstract from PubMed The Cdc48 ATPase (p97 or VCP in mammals) and its cofactor Ufd1/Npl4 extract poly-ubiquitinated proteins from membranes or macromolecular complexes for subsequent degradation by the proteasome. How Cdc48 processes its diverse and often well-folded substrates is unclear. Here, we report cryo-EM structures of the Cdc48 ATPase in complex with Ufd1/Npl4 and poly-ubiquitinated substrate. The structures show that the Cdc48 complex initiates substrate processing by unfolding a ubiquitin molecule. The unfolded ubiquitin molecule binds to Npl4 and projects its N-terminal segment through both hexameric ATPase rings. Pore loops of the second ring form a staircase that acts as a conveyer belt to move the polypeptide through the central pore. Inducing the unfolding of ubiquitin allows the Cdc48 ATPase complex to process a broad range of substrates. Substrate processing by the Cdc48 ATPase complex is initiated by ubiquitin unfolding.,Twomey EC, Ji Z, Wales TE, Bodnar NO, Ficarro SB, Marto JA, Engen JR, Rapoport TA Science. 2019 Jun 27. pii: science.aax1033. doi: 10.1126/science.aax1033. PMID:31249135 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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