Determination of Pectate Lyase Activity in Laundry Detergents

2021 ◽  
Author(s):  
Franco Pala ◽  
Weidong Li ◽  
Christie Dame
Keyword(s):  
Pectate Lyase ◽  
Laundry Detergents ◽  
Lyase Activity

The HrpW protein ofLonsdalea quercinaN-5-1 has pectate lyase activity and is required for full bacterial virulence

2014 ◽  
Vol 54 (10) ◽  
pp. 1126-1135 ◽  
Author(s):  
Li Yang ◽  
Bochao Xu ◽  
Wei He ◽  
Liqun Zhang
Keyword(s):  
Pectate Lyase ◽  
Bacterial Virulence ◽  
Lyase Activity

scholarly journals RNA chaperones Hfq and ProQ play a key role in the virulence of the plant pathogenic bacterium Dickeya dadantii

2021 ◽  
Author(s):  
Simon Leonard ◽  
Camille Villard ◽  
William Nasser ◽  
Sylvie Reverchon ◽  
Florence Hommais
Keyword(s):  
Extracellular Enzymes ◽  
Pectate Lyase ◽  
Soft Rot ◽  
Pathogenic Bacterium ◽  
Growth Defect ◽  
Dickeya Dadantii ◽  
Genes Encoding ◽  
Lyase Activity ◽  
Rna Chaperones ◽  
Post Transcriptional Regulation

Dickeya dadantii is an important pathogenic bacterium that infects a number of crops including potato and chicory. While extensive works have been carried out on the control of the transcription of its genes encoding the main virulence functions, little information is available on the post-transcriptional regulation of these functions. We investigated the involvement of the RNA chaperones Hfq and ProQ in the production of the main D. dadantii virulence functions. Phenotypic assays on the hfq and proQ mutants showed that inactivation of hfq resulted in a growth defect, a modified capacity for biofilm formation and strongly reduced motility, and in the production of degradative extracellular enzymes (proteases, cellulase and pectate lyases). Accordingly, the hfq mutant failed to cause soft rot on chicory leaves. The proQ mutant had reduced resistance to osmotic stress, reduced extracellular pectate lyase activity compared to the wild-type strain, and reduced virulence on chicory leaves. Most of the phenotypes of the hfq and proQ mutants were related to the low amounts of mRNA of the corresponding virulence factors. Complementation of the double mutant hfq-proQ by each individual protein and cross-complementation of each chaperone suggested that they might exert their effects via partially overlapping but different sets of targets. Overall, it clearly appeared that the two Hfq and ProQ RNA chaperones are important regulators of pathogenicity in D. dadantii. This underscores that virulence genes are regulated post transcriptionally by non-coding RNAs.

scholarly journals HrpW of Erwinia amylovora, a New Harpin That Contains a Domain Homologous to Pectate Lyases of a Distinct Class

1998 ◽  
Vol 180 (19) ◽  
pp. 5203-5210 ◽  
Author(s):  
Jihyun F. Kim ◽  
Steven V. Beer
Keyword(s):  
Plant Cell Wall ◽  
Erwinia Amylovora ◽  
Pectate Lyase ◽  
Hypersensitive Reaction ◽  
Host Tissue ◽  
Wild Type ◽  
Pectate Lyases ◽  
Heat Stable ◽  
Lyase Activity ◽  
Type Strains

ABSTRACT Harpins, such as HrpN of Erwinia amylovora, are extracellular glycine-rich proteins that elicit the hypersensitive reaction (HR). We identified hrpW of E. amylovora, which encodes a protein similar to known harpins in that it is acidic, rich in glycine and serine, and lacks cysteine. A putative HrpL-dependent promoter was identified upstream ofhrpW, and Western blot analysis of hrpL mutants indicated that the production of HrpW is regulated by hrpL. HrpW is secreted via the Hrp (type III) pathway based on analysis of wild-type strains and hrp secretion mutants. When infiltrated into plants, HrpW induced rapid tissue collapse, which required active plant metabolism. The HR-eliciting activity was heat stable and protease sensitive. Thus, we concluded that HrpW is a new harpin. HrpW of E. amylovora consists of two domains connected by a Pro and Ser-rich sequence. A fragment containing the N-terminal domain was sufficient to elicit the HR. Although no pectate lyase activity was detected, the C-terminal region of HrpW is homologous to pectate lyases of a unique class, suggesting that HrpW may be targeted to the plant cell wall. Southern analysis indicated that hrpW is conserved among several Erwiniaspecies, and hrpW, provided in trans, enhanced the HR-inducing ability of a hrpN mutant. However, HrpW did not increase the virulence of a hrpN mutant in host tissue, and hrpW mutants retained the wild-type ability to elicit the HR in nonhosts and to cause disease in hosts.

scholarly journals Arabidopsis thaliana Expresses Multiple Lines of Defense to Counterattack Erwinia chrysanthemi

2007 ◽  
Vol 20 (7) ◽  
pp. 794-805 ◽  
Author(s):  
Mathilde Fagard ◽  
Alia Dellagi ◽  
Camille Roux ◽  
Claude Périno ◽  
Martine Rigault ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Signaling Pathways ◽  
Oxidative Burst ◽  
Pectate Lyase ◽  
Erwinia Chrysanthemi ◽  
Secreted Proteins ◽  
Type Ii Secretion ◽  
Susceptible Host ◽  
Pectate Lyases ◽  
Lyase Activity

Many taxonomically diverse plant species are attacked by Erwinia chrysanthemi, a member of the causal agents of soft-rotting diseases. Symptom development is due to the collective action of pectin-degrading enzymes secreted by the bacterium through a type II secretion system (T2SS). Using Arabidopsis thaliana as a susceptible host, we show that plants respond to E. chrysanthemi 3937 by expressing cell-wall reactions, production of an oxidative burst, and activation of salicylic acid (SA) and jasmonic acid (JA) or ethylene (ET) signaling pathways. We found that the oxidative burst is mainly generated via the expression of the AtrbohD gene, constitutes a barrier of resistance to bacterial attack, and acts independently of the SA-mediated response. To determine the importance of T2SS-secreted proteins in elicitation of these defenses, we used a T2SS deficient mutant and purified enzymatic preparations of representative members of strain 3937 pectate lyase activity. The T2SS-secreted proteins were responsible only partially for the activation of SA and JA or ET signaling pathways observed after infection with the wild-type bacterium and were not involved in the expression of other identified defense reactions. Our study shows the differential role played by pectate lyases isoenzymes in this process and highlights the complexity of the host immune network, which is finely controlled by the bacterium.

scholarly journals The Role of Pectate Lyase and the Jasmonic Acid Defense Response in Pseudomonas viridiflava Virulence

2007 ◽  
Vol 20 (2) ◽  
pp. 146-158 ◽  
Author(s):  
Katrin Jakob ◽  
Joel M. Kniskern ◽  
Joy Bergelson
Keyword(s):  
Jasmonic Acid ◽  
Defense Response ◽  
Induced Defense ◽  
Pectate Lyase ◽  
Defense Responses ◽  
Wild Populations ◽  
Pseudomonas Viridiflava ◽  
Lyase Activity ◽  
Induced Defense Responses

Pseudomonas viridiflava is a common pathogen of Arabidopsis thaliana in wild populations, yet very little is known about mechanisms of resistance and virulence in this interaction. We examined the induced defense response of A. thaliana to several strains of P. viridiflava collected from this host by quantifying the expression of PR-1 and LOX2/PDF1.2, which serve as markers for induction of the salicylic and jasmonic acid (JA) pathways, respectively. Growth of these strains then was assessed on Col-0, the fad3/7/8 and coi1-1 mutants deficient in JA- and ethylene (ET)-induced defense responses, and the sid2-1 mutant deficient in salicylic acid-induced defense responses. All strains of P. viridiflava induced high expression of LOX2 and PDF1.2 on Col-0. In contrast, PR-1 expression was delayed and reduced relative to PDF1.2 expression. Additionally, three of four P. viridiflava strains were more virulent on fad3/7/8 relative to Col-0, whereas all strains were more virulent on coi1-1 relative to Col-0, indicating that P. viridi-flava generally may be suppressed by JA/ET-mediated defense responses. In contrast, no increase in the growth of P. viridiflava strains was observed in the sid2-1 mutant relative to Col-0. Parallel experiments were performed with the closely related P. syringae pv. tomato for comparative purposes. In addition, we assessed the role of pectate lyase and the alternative sigma factor HrpL in P. viridiflava virulence on A. thaliana and found that pectate lyase activity is correlated with virulence, whereas the removal of pectate lyase or HrpL significantly reduced virulence.

Rhizobium etli HrpW is a pectin-degrading enzyme and differs from phytopathogenic homologues in enzymically crucial tryptophan and glycine residues

Microbiology ◽  
2009 ◽  
Vol 155 (9) ◽  
pp. 3045-3054 ◽  
Author(s):  
Maarten Fauvart ◽  
Natalie Verstraeten ◽  
Bruno Dombrecht ◽  
Ruth Venmans ◽  
Serge Beullens ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Plant Cell Wall ◽  
Biochemical Characterization ◽  
Sequence Data ◽  
Functional Characterization ◽  
Pectate Lyase ◽  
Site Directed Mutagenesis ◽  
Rhizobium Etli ◽  
Lyase Activity

While establishing a nitrogen-fixing symbiosis with leguminous plants, rhizobia are faced with the problem of penetrating the plant cell wall at several stages of the infection process. One of the major components of this barrier is pectin, a heteropolysaccharide composed mainly of galacturonic acid subunits. So far, no enzymes capable of degrading pectin have been isolated from rhizobia. Here, we make an inventory of rhizobial candidate pectinolytic enzymes based on available genome sequence data and present an initial biochemical and functional characterization of a protein selected from this list. Rhizobium etli hrpW is associated with genes encoding a type III secretion system, a macromolecular structure that allows bacteria to directly inject so-called effector proteins into a eukaryotic host's cell cytosol and an essential virulence determinant of many Gram-negative pathogenic bacteria. In contrast to harpin HrpW from phytopathogens, R. etli HrpW possesses pectate lyase activity and is most active on highly methylated substrates. Through comparative sequence analysis, three amino acid residues crucial for the observed enzymic activity were identified: Trp192, Gly212 and Gly213. Their importance was confirmed by site-directed mutagenesis and biochemical characterization of the resulting proteins, with the tryptophan mutant showing no detectable pectate lyase activity and the double-glycine mutant's activity reduced by about 80 %. Surprisingly, despite hrpW expression being induced specifically on the plant root surface, a knockout mutation of the gene does not appear to affect symbiosis with the common bean Phaseolus vulgaris.

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