4kyo
Alanine-glyoxylate aminotransferase variant K390A in complex with the TPR domain of human Pex5pAlanine-glyoxylate aminotransferase variant K390A in complex with the TPR domain of human Pex5p
Structural highlights
DiseaseAGT1_HUMAN Primary hyperoxaluria type 1. The disease is caused by variants affecting the gene represented in this entry. FunctionAGT1_HUMAN Peroxisomal aminotransferase that catalyzes the transamination of glyoxylate to glycine and contributes to the glyoxylate detoxification (PubMed:10960483, PubMed:12777626, PubMed:24055001, PubMed:23229545, PubMed:26149463). Also catalyzes the transamination between L-serine and pyruvate and contributes to gluconeogenesis from the L-serine metabolism (PubMed:10347152).[1] [2] [3] [4] [5] [6] Publication Abstract from PubMedPeroxisomes entirely rely on the import of their proteome across the peroxisomal membrane. Recognition efficiencies of peroxisomal proteins vary by more than 1000-fold but the molecular rationale behind their subsequent differential import and sorting has remained enigmatic. Using the protein cargo alanine-glyoxylate aminotransferase as a model, we have discovered an unexpected increase from 34% to 80% in peroxisomal import efficiency of a single-residue mutant. By high-resolution structural analysis, we found that it is the recognition receptor PEX5 that adapts its conformation for high-affinity binding rather than the cargo protein signal motif as previously thought. During receptor recognition, the binding cavity of the receptor shrinks to one third of its original volume. This process is impeded in the wild-type protein cargo because of a bulky side chain within the recognition motif, which blocks contraction of the PEX5 binding cavity. Our data provide a new insight on direct protein import efficiency by removal rather than addition of an apparent specific sequence signature that is generally applicable to peroxisomal matrix proteins and to other receptor recognition processes. Ligand-induced compaction of the PEX5 receptor-binding cavity impacts protein import efficiency into peroxisomes.,Fodor K, Wolf J, Reglinski K, Passon DM, Lou Y, Schliebs W, Erdmann R, Wilmanns M Traffic. 2014 Nov 5. doi: 10.1111/tra.12238. PMID:25369882[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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