Structure of a group A streptococcal phage-encoded virulence factor reveals a catalytically active triple-stranded β-helix

Smith, Nicola L.; Taylor, Edward J.; Lindsay, Anna-Marie; Charnock, Simon J.; Turkenburg, J.P.; Dodson, E.J.; Davies, G.J.; Black, Gary W.

doi:10.1073/pnas.0504782102

Cited by 70 publications

(65 citation statements)

References 44 publications

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“…Comparable structures include the triple β-helix regions of phage T4 gp12 (41) and gp5 (42), the K1F endosialidase (43) and endo-N-acetylneuramidase (29), streptococcal (pro)phage HylP1 and Hylp2 (44,45), the phage P22 cell penetrating needle gp26 (40), and phage Phi29 tail-spike (46). However, the most similar structures are those of phage P2 gpV (Fig.…”

Section: Discussionmentioning

confidence: 99%

Structure of the receptor-binding carboxy-terminal domain of bacteriophage T7 tail fibers

Garcia-Doval

Raaij

2012

Proc. Natl. Acad. Sci. U.S.A.

108

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The six bacteriophage T7 tail fibers, homo-trimers of gene product 17, are thought to be responsible for the first specific, albeit reversible, attachment to Escherichia coli lipopolysaccharide. The protein trimer forms kinked fibers comprised of an amino-terminal tail-attachment domain, a slender shaft, and a carboxyl-terminal domain composed of several nodules. Previously, we expressed, purified, and crystallized a carboxyl-terminal fragment comprising residues 371-553. Here, we report the structure of this protein trimer, solved using anomalous diffraction and refined at 2 Å resolution. Amino acids 371-447 form a tapered pyramid with a triangular cross-section composed of interlocked β-sheets from each of the three chains. The triangular pyramid domain has three α-helices at its narrow end, which are connected to a carboxyl-terminal three-blade β-propeller tip domain by flexible loops. The monomers of this tip domain each contain an eight-stranded β-sandwich. The exact topology of the β-sandwich fold is novel, but similar to that of knob domains of other viral fibers and the phage Sf6 needle. Several host-range change mutants have been mapped to loops located on the top of this tip domain, suggesting that this surface of the tip domain interacts with receptors on the cell surface.bacterial viruses | caudovirales | crystallography | infection | Podoviridae B acteriophages (bacterial viruses or phages) are important biological model systems and, because of the high specificity for their host bacteria, have found application in phage typing, food security, and phage therapy (1). Escherichia coli phage T7 is a member of the Podoviridae family of the Caudovirales (tailed phages) order (2). T7 is composed of an icosahedral capsid with a 20-nm short tail at one of the vertices (3, 4). The capsid is formed by the shell protein gene product (gp) 10 and encloses a DNA of 40 kb. A cylindrical structure composed of gp14, gp15, and gp16 is present inside the capsid (5), attached to the special vertex formed by the connector, a circular dodecamer of gp8 (6). Gp11 and gp12 form the tail; gp13, gp6.7, and gp7.3 have also been shown to be part of the virion and to be necessary for infection, although their location has not been established (7,8). Although extensive electron microscopy studies have been performed on phage T7 (3-6, 9), crystallographic studies have so far been limited to its nonstructural proteins.The main portion of the tail is composed of gp12, a large protein of which six copies are present (10); the small gp11 protein is also located in the tail (5). Attached to the tail are six fibers, each containing three copies of the gp17 protein. T7 tail fibers are elongated homo-trimers, which are responsible for initial, reversible, host cell recognition. A second, irreversible, decisionmaking interaction with the bacterial membrane is presumably mediated by one or more of the tail-tube proteins. DNA transfer into the host is then mediated by an extension formed by gp14-16 (7, 8, 11). Previously, we have reported t...

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Section: Discussionmentioning

confidence: 99%

Structure of the receptor-binding carboxy-terminal domain of bacteriophage T7 tail fibers

Garcia-Doval

Raaij

2012

Proc. Natl. Acad. Sci. U.S.A.

108

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“…Recently, a GH69 enzyme was found to be a lyase, and reassigned to a polysaccharide lyase family, PL16. 60,61) Phosphorylases have been assigned EC numbers of glycosyltransferases (2.4.1. ) according to the apparent reaction scheme.…”

Section: Reclassification From Gt36 To Gh94: Gh-type In-mentioning

confidence: 99%

New Structural Insights on Carbohydrate-active Enzymes

Fushinobu¹,

Hidaka²,

Miyanaga³

et al. 2007

J. Appl. Glycosci.

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Polysaccharides show a huge degree of diversity owing to their variety of sugar components (aldoses, ketoses and their stereoisomers), the variety of glycosidic bonds (e.g., α 1,4 , α 1,6 , β 1,4 , β 1,3 , etc.), different degrees of polymerization, and different degrees of branching. Therefore, they can be involved in many types of biological function with distinct physicochemical characteristics. It is especially intriguing that α and β glucans, such as amylose (starch) and cellulose, are built from the same glucose units, differing only in the anomeric configurations of glycosidic bonds. Enzymes that hydrolyze these glucans, amylases and cellulases, are the two largest groups of glycoside hydrolases, and have been studied for a long time. A framework to discuss a whole variety of glycoside hydrolases with their three dimensional structural aspects has been established within the last 15 years. In the late 1980s, Henrissat et al. began classification of the amino acid sequences of enzymes, focusing on cellulases and hemicellulases. 1) At the earliest stage of their classification, the α amylase family was treated as belonging to a separate system.2) In 1991, the naming system of the families changed from alphabetical to numerical, and the system expanded to 35 "glycosyl hydrolase" families, incorporating three well known amylase families, GH13 (retaining α amylase family), GH14 (inverting β amylase family), and GH15 (inverting glucoamylase family), as well as many other enzymes.3) All enzymes cleaving, modifying, and creating glycosidic bonds, and modules binding to carbohydrates have been incorporated into the CAZy database (http: www.cazy.org CAZY ). Glycoside hydrolase (GH) families now include enzymes that hydrolyze the glycosidic bonds between two or more carbohydrates or between a carbohydrate and a non carbohydrate moiety. At present, there are 101 families in the GH class ( Fig. 1; note, five have been deleted or reassigned to other classes), and it will continue to grow.The first 3 D structure of a glycoside hydrolase to be determined was that of hen egg white lysozyme (classified into GH22) in the mid 1960s.4) Even in the early 1990s, however, only a limited number of GH enzyme structures were available. Henrissat and colleagues took amino acid sequence information as the primary basis for classification, but they also used hydrophobic cluster analysis from the earliest stage, trying to incorporate as much 3 D structure based information as possible.5) The significant advances in structural studies of GH enzymes over the last decade have indicated that these enzymes show a vast array of tertiary scaffolds, described as "a marketplace of different structures". 6)Our group has been trying to solve crystal structures of useful enzymes for use in bioindustry. Two of these were the first crystal structures within the GH42 and GH57 families, 7,8) and we then began to focus on CAZy enzymes belonging to structurally unknown families. We have since solved two more GH families, and provided the first crystal s...

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“…Crystal structures of lyases belonging to families PL-1, -3, -4, -5, -6, -7, -8, -9, -10, -16, and -18 have been determined. These enzymes are grouped into six structural categories: (i) the parallel ␤-helix in PL-1 (13,14,16,17,55,56), -3 (57), -6 (58), and -9 (20); (ii) the ␣/␣-barrel in PL-5 (59) and -10 (60, 61); (iii) the ␣/␣-barrel plus anti-parallel ␤-sheet in PL-8 (29,(62)(63)(64)(65)(66); (iv) the ␤-sandwich plus ␤-sheet in PL-4 (33); (v) the ␤-jelly roll in PL-7 (27,67,68) and -18; and (vi) the triplestrand ␤-helix in PL-16 (69). The folds and substrates of polysaccharide lyases are summarized in Table 1.…”

Section: Resultsmentioning

confidence: 99%

A Novel Structural Fold in Polysaccharide Lyases

Ochiai

Itoh

Maruyama

et al. 2007

Journal of Biological Chemistry

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Rhamnogalacturonan (RG) lyase produced by plant pathogenic and saprophytic microbes plays an important role in degrading plant cell walls. An extracellular RG lyase YesW from saprophytic Bacillus subtilis is a member of polysaccharide lyase family 11 and cleaves glycoside bonds in polygalacturonan as well as RG type-I through a ␤-elimination reaction. Crystal structures of YesW and its complex with galacturonan disaccharide, a reaction product analogue, were determined at 1.4 and 2.5 Å resolutions with final R-factors of 16.4% and 16.6%, respectively. The enzyme is composed of an eight-bladed ␤-propeller with a deep cleft in the center as a basic scaffold, and its structural fold has not been seen in polysaccharide lyases analyzed thus far. Structural analysis of the disaccharide-bound YesW and a site-directed mutagenesis study suggested that Arg-452 and Lys-535 stabilize the carboxyl group of the acidic polysaccharide molecule and Tyr-595 makes a stack interaction with the sugar pyranose ring. In addition to amino acid residues binding to the disaccharide, one calcium ion, which is coordinated by Asp-401, Glu-422, His-363, and His-399, may mediate the enzyme activity. This is, to our knowledge, the first report of a new structural category with a ␤-propeller fold in polysaccharide lyases and provides structural insights into substrate binding by RG lyase.Plant cell wall degradation is essential for plant pathogenic and saprophytic microbes to invade plants. The plant cell wall mainly consists of polysaccharides and proteins, with polysaccharides being more abundant. These polysaccharides are divided into three groups, cellulose, hemicellulose, and pectin (1). Pectin is more soluble in water than cellulose and hemicellulose, suggesting that this polysaccharide is the preferred target for plant-associated microbes. Pectin is further divided to three regions, i.e. polygalacturonan, rhamnogalacturonan type-I (RG-I), 2 and rhamnogalacturonan type-II (RG-II). In pectin molecules, polygalacturonan is present as a linear backbone, and RG-I and RG-II are attached to the backbone as branched chains (2-4). RG-I is a polymer with a disacchariderepeating unit consisting of L-rhamnopyranose and D-galactopyranouronic acid (GalA) as a main chain, and arabinans and galactans are attached to the main chain (5). RG-II has a backbone of polygalacturonan, and its side chains consist of a complex of ϳ30 monosaccharides, including rare sugars such as apiose and aceric acid (6). These plant cell wall polysaccharides become substrates to be degraded through reactions of polysaccharide hydrolases and/or lyases produced by plant pathogenic and saprophytic microbes. Hydrolases cleave glycoside bonds in polysaccharides via hydrolysis, and lyases do so by ␤-elimination reactions (7,8).The degradation pathway for the polygalacturonan region has been characterized extensively in microbes (9 -12). The structure and function relationships of polygalacturonan-degrading enzymes, including hydrolases and lyases have also been well documented (13)(...

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Structure of a group A streptococcal phage-encoded virulence factor reveals a catalytically active triple-stranded β-helix

Cited by 70 publications

References 44 publications

Structure of the receptor-binding carboxy-terminal domain of bacteriophage T7 tail fibers

Structure of the receptor-binding carboxy-terminal domain of bacteriophage T7 tail fibers

New Structural Insights on Carbohydrate-active Enzymes

A Novel Structural Fold in Polysaccharide Lyases

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