Aspartate/asparagine-β-hydroxylase crystal structures reveal an unexpected epidermal growth factor-like domain substrate disulfide pattern
journal contributionposted on 2020-05-14, 09:00 authored by I Pfeffer, L Brewitz, T Krojer, SA Jensen, GT Kochan, NJ Kershaw, KS Hewitson, LA McNeill, H Kramer, M Münzel, RJ Hopkinson, U Oppermann, PA Handford, MA McDonough, CJ Schofield
AspH is an endoplasmic reticulum (ER) membrane-anchored 2-oxoglutarate oxygenase whose C-terminal oxygenase and tetratricopeptide repeat (TPR) domains present in the ER lumen. AspH catalyses hydroxylation of asparaginyl- and aspartyl-residues in epidermal growth factor-like domains (EGFDs). Here we report crystal structures of human AspH, with and without substrate, that reveal substantial conformational changes of the oxygenase and TPR domains during substrate binding. Fe(II)-binding by AspH is unusual, employing only two Fe(II)-binding ligands (His679/His725). Most EGFD structures adopt an established fold with a conserved Cys1–3, 2–4, 5–6 disulfide bonding pattern; an unexpected Cys3–4 disulfide bonding pattern is observed in AspH-EGFD substrate complexes, the catalytic relevance of which is supported by studies involving stable cyclic peptide substrate analogues and by effects of Ca(II) ions on activity. The results have implications for EGFD disulfide pattern processing in the ER and will enable medicinal chemistry efforts targeting human 2OG oxygenases.
We thank the Wellcome Trust, Cancer Research UK, and the Biotechnological and Biological Research Council for funding. M.M. thanks the People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007–2013) under REA grant agreement number 298603 (Marie Curie IEF) for a Fellowship and R.J.H acknowledges a William R. Miller Junior Research Fellowship from St Edmund Hall Oxford. L.B. thanks the Deutsche Forschungsgemeinschaft for a fellowship (BR 5486/2-1). S.A.J. and P.A.H. thank Arthritis Research UK for support (20785). U. O. thanks Arthritis Research UK for support (20522).
CitationNature Communications 2019, 10:4910
Author affiliationDepartment of Chemistry
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