The yeast Cvt receptor Atg19 and the paralog Atg34 are NBR1 homologs. (A) Domain architecture of NBR1 homologs from humans, the plant Arabidopsis thaliana, the filamentous fungus C. thermophilum, fission yeast S. pombe, S. cerevisiae Atg19 and Atg34. (B) Comparison of FW domain structures between human ILRUN (PDB accession no. 6VHI), C. thermophilum (Ct NBR1; PDB accession no. 7VQO), and the ABD structures from yeast Atg19 (PDB accession no. 2KZB) and Atg34 (PDB accession no. 2KZK). Structural alignment of the ILRUN FW domain (blue) to the Atg34 ABD/FW domain (magenta) obtained by a VAST search of the PDB database. A sequence alignment with positions of the structural elements (β strands) is shown below the structures. Despite only 7% sequence identity the alignment gives a root-mean-square deviation of 1.90 Å over a 60 amino acid sequence. (C) Atg34 contains a PB1 domain fold. The AlphaFold structure predicted with 90% confidence for the N-terminal domain of Atg34 (green) is a PB1 domain that can be structurally aligned to the solved structure (PDB accession no. 6TGN) of the PB1 domain of Arabidopsis thaliana (magenta). The structures were aligned using PyMol.