title: Structural analysis of a bacterial exo-α-D-N-acetylglucosaminidase in complex with an unusual disaccharide found in class III mucin.
abstract: CpGH89 is a family 89 glycoside hydrolase with exo-α-D-N-acetylglucosaminidase activity that is produced by the human and animal pathogen Clostridium perfringens. This enzyme is active on the α-D-GlcpNAc-(1 → 4)-D-Galp motif that is displayed on the class III mucins within the gastric mucosa. Other members of this enzyme family, such as human NAGLU, are active on heparan. A truncated version of CpGH89 was rendered inactive through the mutation of two key catalytic residues, the protein crystallized and its structure determined in complex with α-D-GlcpNAc-(1 → 4)-D-Galp to reveal the molecular details of how this unique disaccharide is recognized by CpGH89. An analysis of this substrate complex not only provides insight into how this enzyme selects for its mucin-presented substrate but also advances our understanding of how its clinically relevant mammalian counterparts are specific for heparan.
authors.affiliation: Department of Biochemistry and Microbiology,  University of Victoria, PO Box 3055 STN CSC, Victoria, BC,  Canada V8W 3P6.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Ficko-Blean
authors.forename: Alisdair B
authors.initials: AB
authors.lastname: Boraston
mesh_terms: D000118:Acetylglucosaminidase / Q000737:chemistry* / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D020134:Catalytic Domain; D003016:Clostridium perfringens / Q000201:enzymology*; D003460:Crystallization; D018360:Crystallography, X-Ray; D004187:Disaccharides / Q000378:metabolism*; D008969:Molecular Sequence Data; D009077:Mucins / Q000737:chemistry*; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D004187:Disaccharides; D009077:Mucins; C033079:alpha-N-acetyl-D-glucosaminidase; D000118:Acetylglucosaminidase
references.citation: Hum Mutat. 2001 Oct;18(4):264-81
references.pmid: 11668611
references.citation: Biochem J. 1997 Jan 15;321 ( Pt 2):557-9
references.pmid: 9020895
references.citation: Methods Mol Biol. 1996;57:203-15
references.pmid: 8850007
references.citation: Glycobiology. 2008 Oct;18(10):799-805
references.pmid: 18635885
references.citation: Nature. 1992 Jan 30;355(6359):472-5
references.pmid: 18481394
references.citation: Acta Crystallogr D Biol Crystallogr. 1999 Oct;55(Pt 10):1718-25
references.pmid: 10531521
references.citation: Nat Rev Microbiol. 2011 Apr;9(4):265-78
references.pmid: 21407243
references.citation: J Biol Chem. 2011 Feb 25;286(8):6479-89
references.pmid: 21177247
references.citation: Eur J Biochem. 1976 Aug 1;67(1):129-36
references.pmid: 964236
references.citation: J Comput Chem. 2008 Mar;29(4):622-55
references.pmid: 17849372
references.citation: Acta Crystallogr D Biol Crystallogr. 2010 Jan;66(Pt 1):12-21
references.pmid: 20057044
references.citation: Acta Crystallogr D Biol Crystallogr. 1997 May 1;53(Pt 3):240-55
references.pmid: 15299926
references.citation: Nucleic Acids Res. 2003 Jul 1;31(13):3784-8
references.pmid: 12824418
references.citation: Proc Natl Acad Sci U S A. 2008 May 6;105(18):6560-5
references.pmid: 18443291
references.citation: J Biol Chem. 2009 Apr 10;284(15):9876-84
references.pmid: 19193644
references.citation: Nucleic Acids Res. 2010 Jul;38(Web Server issue):W529-33
references.pmid: 20478830
references.citation: Acta Crystallogr D Biol Crystallogr. 2004 Dec;60(Pt 12 Pt 1):2126-32
references.pmid: 15572765