title: Crystal structure of a type II dehydroquinate dehydratase-like protein from Bifidobacterium longum.
abstract: Dehydroquinate dehydratase (DHQD) catalyzes the third step in the biosynthetic shikimate pathway. Here we identify a Bifidobacterium longum protein with high sequence homology to type II DHQDs but no detectable DHQD activity under standard assay conditions. A crystal structure reveals that the B. longum protein adopts a DHQD-like tertiary structure but a distinct quaternary state. Apparently forming a dimer, the B. longum protein lacks the active site aspartic acid contributed from a neighboring protomer in the type II DHQD dodecamer. Relating to the absence of protein-protein interactions established in the type II DHQD dodecameric assembly, substantial conformational changes distinguish the would-be active site of the B. longum protein. As B. longum possess no other genes with homology to known DHQDs, these findings imply a unique DHQD activity within B. longum.
authors.affiliation: Center for Structural Genomics of Infectious Diseases and Department of Molecular Pharmacology and Biological Chemistry, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Samuel H
authors.initials: SH
authors.lastname: Light
authors.forename: Sankar N
authors.initials: SN
authors.lastname: Krishna
authors.forename: Raymond C
authors.initials: RC
authors.lastname: Bergan
authors.forename: Arnon
authors.initials: A
authors.lastname: Lavie
authors.forename: Wayne F
authors.initials: WF
authors.lastname: Anderson
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001644:Bifidobacterium / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics; D006836:Hydro-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D012765:Shikimic Acid / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D011994:Recombinant Proteins; D012765:Shikimic Acid; D006836:Hydro-Lyases; C020000:3-dehydroquinate dehydratase
references.citation: Acta Crystallogr D Biol Crystallogr. 2005 Apr;61(Pt 4):458-64
references.pmid: 15805601
references.citation: Acta Crystallogr D Biol Crystallogr. 1999 Jan;55(Pt 1):247-55
references.pmid: 10089417
references.citation: J Biol Chem. 2011 Feb 4;286(5):3531-9
references.pmid: 21087925
references.citation: Crit Rev Biochem Mol Biol. 1990;25(5):307-84
references.pmid: 2279393
references.citation: Nat Rev Drug Discov. 2007 Jan;6(1):29-40
references.pmid: 17159923
references.citation: Acta Crystallogr D Biol Crystallogr. 2004 Mar;60(Pt 3):463-71
references.pmid: 14993670
references.citation: Structure. 2002 Apr;10(4):493-503
references.pmid: 11937054
references.citation: Biochem J. 1977 Mar 1;161(3):599-607
references.pmid: 139889
references.citation: Protein Expr Purif. 2002 Jun;25(1):1-7
references.pmid: 12071692
references.citation: Nat Struct Biol. 1999 Jun;6(6):521-5
references.pmid: 10360352
references.citation: Biochem J. 1996 Oct 15;319 ( Pt 2):333-6
references.pmid: 8912664
references.citation: Acta Crystallogr D Biol Crystallogr. 2004 Dec;60(Pt 12 Pt 1):2126-32
references.pmid: 15572765
references.citation: Proteins. 2003 Jun 1;51(4):616-7
references.pmid: 12784220
references.citation: Biochem Soc Trans. 2003 Jun;31(Pt 3):548-52
references.pmid: 12773154
references.citation: Biochem J. 1986 Nov 1;239(3):699-704
references.pmid: 2950851
references.citation: Nature. 1998 Jun 25;393(6687):801-5
references.pmid: 9655396
references.citation: Methods Enzymol. 1997;276:307-26
references.pmid: 27754618
references.citation: Biochemistry. 2011 Mar 29;50(12):2357-63
references.pmid: 21291284
references.citation: Protein Expr Purif. 2003 Jun;29(2):311-20
references.pmid: 12767824
references.citation: J Biol Chem. 1995 Oct 27;270(43):25827-36
references.pmid: 7592767
references.citation: Protein Expr Purif. 2002 Jun;25(1):8-15
references.pmid: 12071693
references.citation: Biochem J. 1992 Mar 15;282 ( Pt 3):687-95
references.pmid: 1554351