5tke

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Crystal Structure of Eukaryotic Hydrolase

Structural highlights

5tke is a 2 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Gene:	MGEA5, HEXC, KIAA0679, MEA5 (HUMAN)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[OGA_HUMAN] Isoform 1: Cleaves GlcNAc but not GalNAc from O-glycosylated proteins. Can use p-nitrophenyl-beta-GlcNAc and 4-methylumbelliferone-GlcNAc as substrates but not p-nitrophenyl-beta-GalNAc or p-nitrophenyl-alpha-GlcNAc (in vitro) (PubMed:11148210). Does not bind acetyl-CoA and does not have histone acetyltransferase activity (PubMed:24088714).^[1] ^[2] ^[3] ^[4] ^[5] Isoform 3: Cleaves GlcNAc but not GalNAc from O-glycosylated proteins. Can use p-nitrophenyl-beta-GlcNAc as substrate but not p-nitrophenyl-beta-GalNAc or p-nitrophenyl-alpha-GlcNAc (in vitro), but has about six times lower specific activity than isoform 1.^[6]

Publication Abstract from PubMed

Human O-GlcNAcase (hOGA) is the unique enzyme responsible for the hydrolysis of the O-linked beta-N-acetyl glucosamine (O-GlcNAc) modification, an essential protein glycosylation event that modulates the function of numerous cellular proteins in response to nutrients and stress. Here we report crystal structures of a truncated hOGA, which comprises the catalytic and stalk domains, in apo form, in complex with an inhibitor, and in complex with a glycopeptide substrate. We found that hOGA forms an unusual arm-in-arm homodimer in which the catalytic domain of one monomer is covered by the stalk domain of the sister monomer to create a substrate-binding cleft. Notably, the residues on the cleft surface afford extensive interactions with the peptide substrate in a recognition mode that is distinct from that of its bacterial homologs. These structures represent the first model of eukaryotic enzymes in the glycoside hydrolase 84 (GH84) family and provide a crucial starting point for understanding the substrate specificity of hOGA, which regulates a broad range of biological and pathological processes.

Structures of human O-GlcNAcase and its complexes reveal a new substrate recognition mode.,Li B, Li H, Lu L, Jiang J Nat Struct Mol Biol. 2017 Mar 20. doi: 10.1038/nsmb.3390. PMID:28319083^[7]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Gao Y, Wells L, Comer FI, Parker GJ, Hart GW. Dynamic O-glycosylation of nuclear and cytosolic proteins: cloning and characterization of a neutral, cytosolic beta-N-acetylglucosaminidase from human brain. J Biol Chem. 2001 Mar 30;276(13):9838-45. Epub 2001 Jan 8. PMID:11148210 doi:http://dx.doi.org/10.1074/jbc.M010420200
↑ Wells L, Gao Y, Mahoney JA, Vosseller K, Chen C, Rosen A, Hart GW. Dynamic O-glycosylation of nuclear and cytosolic proteins: further characterization of the nucleocytoplasmic beta-N-acetylglucosaminidase, O-GlcNAcase. J Biol Chem. 2002 Jan 18;277(3):1755-61. PMID:11788610
↑ Li J, Huang CL, Zhang LW, Lin L, Li ZH, Zhang FW, Wang P. Isoforms of human O-GlcNAcase show distinct catalytic efficiencies. Biochemistry (Mosc). 2010 Jul;75(7):938-43. PMID:20673219
↑ Schimpl M, Borodkin VS, Gray LJ, van Aalten DM. Synergy of Peptide and Sugar in O-GlcNAcase Substrate Recognition. Chem Biol. 2012 Feb 24;19(2):173-8. PMID:22365600 doi:10.1016/j.chembiol.2012.01.011
↑ Rao FV, Schuttelkopf AW, Dorfmueller HC, Ferenbach AT, Navratilova I, van Aalten DM. Structure of a bacterial putative acetyltransferase defines the fold of the human O-GlcNAcase C-terminal domain. Open Biol. 2013 Oct 2;3(10):130021. PMID:24088714 doi:http://dx.doi.org/10.1098/rsob.130021
↑ Li J, Huang CL, Zhang LW, Lin L, Li ZH, Zhang FW, Wang P. Isoforms of human O-GlcNAcase show distinct catalytic efficiencies. Biochemistry (Mosc). 2010 Jul;75(7):938-43. PMID:20673219
↑ Li B, Li H, Lu L, Jiang J. Structures of human O-GlcNAcase and its complexes reveal a new substrate recognition mode. Nat Struct Mol Biol. 2017 Mar 20. doi: 10.1038/nsmb.3390. PMID:28319083 doi:http://dx.doi.org/10.1038/nsmb.3390