5nv4

UDP-Glucose Glycoprotein Glucosyltransferase from Chaetomium thermophilum double mutant D611C:G1050C

spinqualitylabelsall models 5nv4, resolution 2.78Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 5nv4 is a 1 chain structure with sequence from Chaetomium thermophilum var. thermophilum DSM 1495. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.78Å Ligands: BMA, FMT, NAG Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G0SB58_CHATD Publication Abstract from PubMed Glycoproteins traversing the eukaryotic secretory pathway begin life in the endoplasmic reticulum (ER), where their folding is surveyed by the 170-kDa UDP-glucose:glycoprotein glucosyltransferase (UGGT). The enzyme acts as the single glycoprotein folding quality control checkpoint: it selectively reglucosylates misfolded glycoproteins, promotes their association with ER lectins and associated chaperones, and prevents premature secretion from the ER. UGGT has long resisted structural determination and sequence-based domain boundary prediction. Questions remain on how this single enzyme can flag misfolded glycoproteins of different sizes and shapes for ER retention and how it can span variable distances between the site of misfold and a glucose-accepting N-linked glycan on the same glycoprotein. Here, crystal structures of a full-length eukaryotic UGGT reveal four thioredoxin-like (TRXL) domains arranged in a long arc that terminates in two beta-sandwiches tightly clasping the glucosyltransferase domain. The fold of the molecule is topologically complex, with the first beta-sandwich and the fourth TRXL domain being encoded by nonconsecutive stretches of sequence. In addition to the crystal structures, a 15-A cryo-EM reconstruction reveals interdomain flexibility of the TRXL domains. Double cysteine point mutants that engineer extra interdomain disulfide bridges rigidify the UGGT structure and exhibit impaired activity. The intrinsic flexibility of the TRXL domains of UGGT may therefore endow the enzyme with the promiscuity needed to recognize and reglucosylate its many different substrates and/or enable reglucosylation of N-linked glycans situated at variable distances from the site of misfold. Interdomain conformational flexibility underpins the activity of UGGT, the eukaryotic glycoprotein secretion checkpoint.,Roversi P, Marti L, Caputo AT, Alonzi DS, Hill JC, Dent KC, Kumar A, Levasseur MD, Lia A, Waksman T, Basu S, Soto Albrecht Y, Qian K, McIvor JP, Lipp CB, Siliqi D, Vasiljevic S, Mohammed S, Lukacik P, Walsh MA, Santino A, Zitzmann N Proc Natl Acad Sci U S A. 2017 Jul 24. pii: 201703682. doi:, 10.1073/pnas.1703682114. PMID:28739903 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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