1dl5

PROTEIN-L-ISOASPARTATE O-METHYLTRANSFERASE

spinqualitylabelsall models 1dl5, resolution 1.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1dl5 is a 2 chain structure with sequence from Thermotoga maritima. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.8Å Ligands: CD, CL, SAH Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function PIMT_THEMA Catalyzes the methyl esterification of L-isoaspartyl residues in peptides and proteins that result from spontaneous decomposition of normal L-aspartyl and L-asparaginyl residues. It plays a role in the repair and/or degradation of damaged proteins. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND: Formation of isoaspartyl residues is one of several processes that damage proteins as they age. Protein L-isoaspartate (D-aspartate) O-methyltransferase (PIMT) is a conserved and nearly ubiquitous enzyme that catalyzes the repair of proteins damaged by isoaspartyl formation. RESULTS: We have determined the first structure of a PIMT from crystals of the T. maritima enzyme complexed to S-adenosyl-L-homocysteine (AdoHcy) and refined it to 1.8 A resolution. Although PIMT forms one structural unit, the protein can be divided functionally into three subdomains. The central subdomain closely resembles other S-adenosyl-L-methionine-dependent methyltransferases but bears a striking alteration of topological connectivity, which is not shared by any other member of this family. Rather than arranged as a mixed beta sheet with topology 6 upward arrow7 downward arrow5 upward arrow4 upward arrow1 upward arrow2 upward arrow3 upward arrow, the central sheet of PIMT is reorganized to 7 upward arrow6 downward arrow5 upward arrow4 upward arrow1 upward arrow2 upward arrow3 upward arrow. AdoHcy is largely buried between the N-terminal and central subdomains by a conserved and largely hydrophobic loop on one rim of the binding cleft, and a conserved Ser/Thr-rich beta strand on the other. The Ser/Thr-rich strand may provide hydrogen bonds for specific interactions with isoaspartyl substrates. The side chain of Ile-206, a conserved residue, crosses the cleft, restricting access to the donor methyl group to a deep well, the putative isoaspartyl methyl acceptor site. CONCLUSIONS: The structure of PIMT reveals a unique modification of the methyltransferase fold along with a site for specific recognition of isoaspartyl substrates. The sequence conservation among PIMTs suggests that the current structure should prove a reliable model for understanding the repair of isoaspartyl damage in all organisms. Crystal structure of protein isoaspartyl methyltransferase: a catalyst for protein repair.,Skinner MM, Puvathingal JM, Walter RL, Friedman AM Structure. 2000 Nov 15;8(11):1189-201. PMID:11080641 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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