Human OGA binds substrates in a conserved peptide recognition groove
نویسندگان
چکیده
Modification of cellular proteins with O-GlcNAc (O-linked N-acetylglucosamine) competes with protein phosphorylation and regulates a plethora of cellular processes. O-GlcNAcylation is orchestrated by two opposing enzymes, O-GlcNAc transferase and OGA (O-GlcNAcase or β-N-acetylglucosaminidase), which recognize their target proteins via as yet unidentified mechanisms. In the present study, we uncovered the first insights into the mechanism of substrate recognition by human OGA. The structure of a novel bacterial OGA orthologue reveals a putative substrate-binding groove, conserved in metazoan OGAs. Guided by this structure, conserved amino acids lining this groove in human OGA were mutated and the activity on three different substrate proteins [TAB1 (transforming growth factor-β-activated protein kinase 1-binding protein 1), FoxO1 (forkhead box O1) and CREB (cAMP-response-element-binding protein)] was tested in an in vitro deglycosylation assay. The results provide the first evidence that human OGA may possess a substrate-recognition mechanism that involves interactions with O-GlcNAcylated proteins beyond the GlcNAc-binding site, with possible implications for differential regulation of cycling of O-GlcNAc on different proteins.
منابع مشابه
A MODEL FOR THE BASIC HELIX- LOOPHELIX MOTIF AND ITS SEQUENCE SPECIFIC RECOGNITION OF DNA
A three dimensional model of the basic Helix-Loop-Helix motif and its sequence specific recognition of DNA is described. The basic-helix I is modeled as a continuous ?-helix because no ?-helix breaking residue is found between the basic region and the first helix. When the basic region of the two peptide monomers are aligned in the successive major groove of the cognate DNA, the hydrophobi...
متن کاملStructural insights into the mechanism and inhibition of eukaryotic O-GlcNAc hydrolysis.
O-linked N-acetylglucosamine (O-GlcNAc) modification of specific serines/threonines on intracellular proteins in higher eukaryotes has been shown to directly regulate important processes such as the cell cycle, insulin sensitivity and transcription. The structure, molecular mechanisms of catalysis, protein substrate recognition/specificity of the eukaryotic O-GlcNAc transferase and hydrolase ar...
متن کاملCrystal structure of the conserved subdomain of human protein SRP54M at 2.1 A resolution: evidence for the mechanism of signal peptide binding.
Protein SRP54 is an integral part of the mammalian signal recognition particle (SRP), a cytosolic ribonucleoprotein complex which associates with ribosomes and serves to recognize, bind, and transport proteins destined for the membrane or secretion. The methionine-rich M-domain of protein SRP54 (SRP54M) binds the SRP RNA and the signal peptide as the nascent protein emerges from the ribosome. A...
متن کاملInvariant chain can bind MHC class II at a site other than the peptide binding groove.
Invariant chain binds to class II molecules and guides them to the cell surface via the endosomes. Class II-associated invariant chain peptide (CLIP), a conserved sequence in an unstructured region of invariant chain, binds in the peptide binding groove of class II and is thought to be the major contributor to the interaction between invariant chain and class II molecules. However, other intera...
متن کاملStructural analysis of leader peptide binding enables leader-free cyanobactin processing
Regioselective modification of amino acids within the context of a peptide is common to a number of biosynthetic pathways, and many of the resulting products have potential as therapeutics. The ATP-dependent enzyme LynD heterocyclizes multiple cysteine residues to thiazolines within a peptide substrate. The enzyme requires the substrate to have a conserved N-terminal leader for full activity. C...
متن کامل