The Dual Nature of the Wheat Xylanase Protein Inhibitor XIP-I

Payan, F.; Leone, Philippe; Porciero, Sophie; Furniss, Caroline S.M.; Tahir, Tariq A.; Williamson, Gary; Durand, Anne; Manzanares, Paloma; Gilbert, Harry J.; Juge, Nathalie; Roussel, Alain

doi:10.1074/jbc.m404225200

Cited by 118 publications

(51 citation statements)

References 37 publications

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“…Both TAXI and XIP are encoded by gene families which are differently regulated by various forms of stress, such as wounding or infection with the wheat pathogens Fusarium graminearum and Erysiphe graminis [7,8 ,9]. TAXI can only inhibit GH11 xylanases, which are b-jelly roll proteins that fold like a hand with the catalytic glutamine residues in the 'palm', covered by a 'thumb' [10]. TAXI-I Extracellular enzymeinhibitor interactions Misas-Villamil and van der Hoorn 381 However, these interactions are just the tip of the iceberg, as F. graminearum has over 30 different xylanase genes that are induced during infection [13].…”

Section: Wheat Inhibitor Taxi Targets Pathogen Gh11 Xylanasesmentioning

confidence: 99%

“…In contrast to TAXI, XIP-I inhibits both GH10 and GH11 xylanases. The crystal structures of XIP-I in complex with A. nidulans (GH10) and Penicillium funiculosum (GH11) xylanases revealed a striking simultaneous binding of the inhibitor to both target enzymes using two independent enzyme-binding sites ( Figure 2b) [10]. GH10 xylanase inhibition is caused by substratemimicking contacts in the S2 substrate-binding pocket of the xylanase.…”

Section: Wheat Inhibitor Xip-i Targets Fungal Gh11 and Gh10 Xylanasesmentioning

confidence: 99%

“…GH10 xylanase inhibition is caused by substratemimicking contacts in the S2 substrate-binding pocket of the xylanase. GH11 xylanase inhibition is mediated by a loop that sticks in the active site, where an arginine residue directly contacts the catalytic residues of the xylanase ( Figure 2c) [10]. XIP-I is an efficient inhibitor of Botrytis XynBc1 GH11 xylanase [12 ] but it cannot inhibit XylA and XylB GH11 xylanases of F. graminearum [11 ].…”

Section: Wheat Inhibitor Xip-i Targets Fungal Gh11 and Gh10 Xylanasesmentioning

confidence: 99%

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Enzyme–inhibitor interactions at the plant–pathogen interface

Misas-Villamil

Hoorn

2008

Current Opinion in Plant Biology

120

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The plant apoplast during plant-pathogen interactions is an ancient battleground that holds an intriguing range of attacking enzymes and counteracting inhibitors. Examples are pathogen xylanases and polygalacturonases that are inhibited by plant proteins like TAXI, XIP, and PGIP; and plant glucanases and proteases, which are targeted by pathogen proteins such as GIP1, EPI1, EPIC2B, and AVR2. These seven well-characterized inhibitors have different modes of action and many probably evolved from inactive enzymes themselves. Detailed studies of the structures, sequence variation, and mutated proteins uncovered molecular struggles between these enzymes and their inhibitors, resulting in positive selection for variant residues at the contact surface, where single residues determine the outcome of the interaction. Introduction Extracellular plant-pathogen interactions probably existed long before the evolution of pathogen effector translocation systems and plant resistance (R) genes. The molecular basis of these interactions is mostly undiscovered but some have been investigated in detail and reveal intriguing mechanisms. Here we will highlight major recent findings of extracellular enzyme-inhibitor interactions at the plant-pathogen interface.Although extracellular plant-pathogen interactions are complex, they can be simplified by assuming that they evolved in several stages (Figure 1). First, micro-organisms became pathogens by attacking plants using cell-wall-degrading enzymes and other hydrolases ( Figure 1A). In response to this attack, plants secrete inhibitors that suppress these hydrolases ( Figure 1B). Initially, these inhibitors were probably constitutively produced, but upon evolution of pathogen recognition systems the production and secretion of these proteins became inducible, becoming part of the arsenal of pathogenesis-related (PR) proteins. Besides suppression of pathogen attack, counter attack mechanisms also evolved in plants through the induced secretion of hydrolytic enzymes ( Figure 1C). Examples are the well-studied PR proteins including endo-b-1,3-glucanases (PR-2), chitinases (PR-3), and proteases (PR-7) [1 ]. Pathogens, in turn, responded to this counter attack by producing inhibitors that suppress these enzymes ( Figure 1D). The fifth and latest step was a sophisticated refinement of the pathogen recognition system by the evolution of R genes that recognize the manipulation of plant targets by pathogens, inducing a severe defense response that includes cell death ( Figure 1E). Aspects of this simplified model are consistent with the 'zigzag' model for the plant immune system, which explains the suppression of basal defense responses by pathogen effector proteins, followed by the evolution of efficient effector recognition by R proteins [2].Antagonistic interactions between organisms at the molecular level result in enzymes that evade inhibition, and inhibitors that adapt to these new enzymes. These 'molecular struggles' result in positive selection for variation of residues at the interactio...

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Section: Wheat Inhibitor Taxi Targets Pathogen Gh11 Xylanasesmentioning

confidence: 99%

Section: Wheat Inhibitor Xip-i Targets Fungal Gh11 and Gh10 Xylanasesmentioning

confidence: 99%

Section: Wheat Inhibitor Xip-i Targets Fungal Gh11 and Gh10 Xylanasesmentioning

confidence: 99%

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Enzyme–inhibitor interactions at the plant–pathogen interface

Misas-Villamil

Hoorn

2008

Current Opinion in Plant Biology

120

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“…Many orthologs are still annotated in GenBank as putative chitinases (for example, GenBank BAC10141). Payan et al (2004) Glycosidase family 97 proteins (GH97) This family contains two subgroups, each with different catalytic machinery and stereochemical outcome, making it difficult to define the catalytic machinery based on invariant acidic residues. Gloster et al (2008) Glycosidase GH4 and GH109 proteins Proteins from these families would be classified as NAD oxidoreductases based on sequence and structure only.…”

Section: Burmeister Et Al (2000)mentioning

confidence: 99%

Viewing the human microbiome through three-dimensional glasses: integrating structural and functional studies to better define the properties of myriad carbohydrate-active enzymes

2010

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Recent studies have provided an unprecedented view of the trillions of microbes associated with the human body. The human microbiome harbors tremendous diversity at multiple levels: the species that colonize each individual and each body habitat; the genes that are found in each organism's genome; the expression of these genes and the interactions and activities of their protein products. The sources of this diversity are wide-ranging and reflect both environmental and host factors. A major challenge moving forward is defining the precise functions of members of various families of proteins represented in our microbiomes, including the highly diverse carbohydrate-active enzymes (CAZymes) involved in numerous biologically important chemical transformations, such as the degradation of complex dietary polysaccharides. Coupling metagenomic analyses to structural genomics initiatives and to biochemical and other functional assays of CAZymes will be essential for determining how these as well as other microbiome-encoded proteins operate to shape the properties of microbial communities and their human hosts.

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“…E. coli BL21 was transformed with the modified vectors and selected on ampicillin (100 g ϫ ml Ϫ1 ) LB plates. Cells grown at 20°C (0.5 liters) were induced by 4 M isopropyl ␤-D-thiogalactopyranoside at A 600 ϭ 0.6, harvested after 24 h by centrifugation, resuspended in 10 ml of intein-CBD tag buffer (20 (21 nM) were preincubated at 37°C (30 min) in 50 mM sodium acetate, pH 5.5, 5 mM CaCl 2 , 0.1 M NaCl, 0.05% bovine serum albumin (400 l); and insoluble Blue Starch was added (6.25 mg in 600 l). The reaction was stopped after 30 min and activity quantified as for AMY2.…”

Section: Methodsmentioning

confidence: 99%

Mutational Analysis of Target Enzyme Recognition of the β-Trefoil Fold Barley α-Amylase/Subtilisin Inhibitor

Bønsager

Nielsen

Hachem

et al. 2005

Journal of Biological Chemistry

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The barley ␣-amylase/subtilisin inhibitor (BASI) inhibits ␣-amylase 2 (AMY2) with subnanomolar affinity. The contribution of selected side chains of BASI to this high affinity is discerned in this study, and binding to other targets is investigated. Seven BASI residues along the AMY2-BASI interface and four residues in the putative protease-binding loop on the opposite side of the inhibitor were mutated. A total of 15 variants were compared with the wild type by monitoring the ␣-amylase and protease inhibitory activities using Blue Starch and azoalbumin, respectively, and the kinetics of binding to target enzymes by surface plasmon resonance. Generally, the mutations had little effect on k on , whereas the k off values were increased up to 67-fold. The effects on the inhibitory activity, however, were far more pronounced, and the K i values of some mutants on the AMY2-binding side increased 2-3 orders of magnitude, whereas mutations on the other side of the inhibitor had virtually no effect. The mutants K140L, D150N, and E168T lost inhibitory activity, revealing the pivotal role of charge interactions for BASI activity on AMY2. A fully hydrated Ca 2؉ at the AMY2-BASI interface mediates contacts to the catalytic residues of AMY2. Mutations involving residues contacting the solvent ligands of this Ca 2؉ had weaker affinity for AMY2 and reduced sensitivity to the Ca 2؉ modulation of the affinity. These results suggest that the Ca 2؉ and its solvation sphere are integral components of the AMY2-BASI complex, thus illuminating a novel mode of inhibition and a novel role for calcium in relation to glycoside hydrolases.The double-headed barley ␣-amylase/subtilisin inhibitor (BASI) 1 of the Kunitz soybean trypsin inhibitor family acts on proteases of the subtilisin family and the endogenous high pI ␣-amylase (AMY2) but has no effect on the minor isozyme AMY1 that shares 80% sequence identity with AMY2

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The Dual Nature of the Wheat Xylanase Protein Inhibitor XIP-I

Cited by 118 publications

References 37 publications

Enzyme–inhibitor interactions at the plant–pathogen interface

Enzyme–inhibitor interactions at the plant–pathogen interface

Viewing the human microbiome through three-dimensional glasses: integrating structural and functional studies to better define the properties of myriad carbohydrate-active enzymes

Mutational Analysis of Target Enzyme Recognition of the β-Trefoil Fold Barley α-Amylase/Subtilisin Inhibitor

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