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Moroz OV, Blagova E, Lebedev AA, Skov LK, Pache RA, Schnorr KM, Kiemer L, Friis EP, Nymand-Grarup S, Ming L, Ye L, Klausen M, Cohn MT, Schmidt EGW, Davies GJ, Wilson KS. Module walking using an SH3-like cell-wall-binding domain leads to a new GH184 family of muramidases. Acta Crystallogr D Struct Biol 2023; 79:S2059798323005004. [PMID: 37428847 PMCID: PMC10394673 DOI: 10.1107/s2059798323005004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 06/06/2023] [Indexed: 07/12/2023] Open
Abstract
Muramidases (also known as lysozymes) hydrolyse the peptidoglycan component of the bacterial cell wall and are found in many glycoside hydrolase (GH) families. Similar to other glycoside hydrolases, muramidases sometimes have noncatalytic domains that facilitate their interaction with the substrate. Here, the identification, characterization and X-ray structure of a novel fungal GH24 muramidase from Trichophaea saccata is first described, in which an SH3-like cell-wall-binding domain (CWBD) was identified by structure comparison in addition to its catalytic domain. Further, a complex between a triglycine peptide and the CWBD from T. saccata is presented that shows a possible anchor point of the peptidoglycan on the CWBD. A `domain-walking' approach, searching for other sequences with a domain of unknown function appended to the CWBD, was then used to identify a group of fungal muramidases that also contain homologous SH3-like cell-wall-binding modules, the catalytic domains of which define a new GH family. The properties of some representative members of this family are described as well as X-ray structures of the independent catalytic and SH3-like domains of the Kionochaeta sp., Thermothielavioides terrestris and Penicillium virgatum enzymes. This work confirms the power of the module-walking approach, extends the library of known GH families and adds a new noncatalytic module to the muramidase arsenal.
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Affiliation(s)
- Olga V Moroz
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Elena Blagova
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Andrey A Lebedev
- CCP4, STFC Rutherford Appleton Laboratory, Harwell Oxford, Didcot OX11 0QX, United Kingdom
| | - Lars K Skov
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | - Roland A Pache
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | - Kirk M Schnorr
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | - Lars Kiemer
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | - Esben P Friis
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | | | - Li Ming
- Novozymes Investment Co. Ltd, 14 Xinxi Road, Beijing 100085, People's Republic of China
| | - Liu Ye
- Novozymes Investment Co. Ltd, 14 Xinxi Road, Beijing 100085, People's Republic of China
| | - Mikkel Klausen
- Novozymes A/S, Biologiens Vej 2, 2800 Kgs Lyngby, Denmark
| | | | | | - Gideon J Davies
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
| | - Keith S Wilson
- York Structural Biology Laboratory, Department of Chemistry, University of York, York YO10 5DD, United Kingdom
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Jéglot A, Sørensen SR, Schnorr KM, Plauborg F, Elsgaard L. Temperature Sensitivity and Composition of Nitrate-Reducing Microbiomes from a Full-Scale Woodchip Bioreactor Treating Agricultural Drainage Water. Microorganisms 2021; 9:1331. [PMID: 34207422 PMCID: PMC8235139 DOI: 10.3390/microorganisms9061331] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/15/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023] Open
Abstract
Denitrifying woodchip bioreactors (WBR), which aim to reduce nitrate (NO3-) pollution from agricultural drainage water, are less efficient when cold temperatures slow down the microbial transformation processes. Conducting bioaugmentation could potentially increase the NO3- removal efficiency during these specific periods. First, it is necessary to investigate denitrifying microbial populations in these facilities and understand their temperature responses. We hypothesized that seasonal changes and subsequent adaptations of microbial populations would allow for enrichment of cold-adapted denitrifying bacterial populations with potential use for bioaugmentation. Woodchip material was sampled from an operating WBR during spring, fall, and winter and used for enrichments of denitrifiers that were characterized by studies of metagenomics and temperature dependence of NO3- depletion. The successful enrichment of psychrotolerant denitrifiers was supported by the differences in temperature response, with the apparent domination of the phylum Proteobacteria and the genus Pseudomonas. The enrichments were found to have different microbiomes' composition and they mainly differed with native woodchip microbiomes by a lower abundance of the genus Flavobacterium. Overall, the performance and composition of the enriched denitrifying population from the WBR microbiome indicated a potential for efficient NO3- removal at cold temperatures that could be stimulated by the addition of selected cold-adapted denitrifying bacteria.
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Affiliation(s)
- Arnaud Jéglot
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (F.P.); (L.E.)
- WATEC Centre for Water Technology, Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | | | - Kirk M. Schnorr
- Novozymes A/S, Biologiens Vej 2, 2800 Kongens Lyngby, Denmark; (S.R.S.); (K.M.S.)
| | - Finn Plauborg
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (F.P.); (L.E.)
- WATEC Centre for Water Technology, Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark
| | - Lars Elsgaard
- Department of Agroecology, Aarhus University, Blichers Allé 20, 8830 Tjele, Denmark; (F.P.); (L.E.)
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Andersen AS, Sandvang D, Schnorr KM, Kruse T, Neve S, Joergensen B, Karlsmark T, Krogfelt KA. A novel approach to the antimicrobial activity of maggot debridement therapy. J Antimicrob Chemother 2010; 65:1646-54. [PMID: 20542901 PMCID: PMC2904663 DOI: 10.1093/jac/dkq165] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Objectives Commercially produced sterile green bottle fly Lucilia sericata maggots are successfully employed by practitioners worldwide to clean a multitude of chronic necrotic wounds and reduce wound bacterial burdens during maggot debridement therapy (MDT). Secretions from the maggots exhibit antimicrobial activity along with other activities beneficial for wound healing. With the rise of multidrug-resistant bacteria, new approaches to identifying the active compounds responsible for the antimicrobial activity within this treatment are imperative. Therefore, the aim of this study was to use a novel approach to investigate the output of secreted proteins from the maggots under conditions mimicking clinical treatments. Methods cDNA libraries constructed from microdissected salivary glands and whole maggots, respectively, were treated with transposon-assisted signal trapping (TAST), a technique selecting for the identification of secreted proteins. Several putative secreted components of insect immunity were identified, including a defensin named lucifensin, which was produced recombinantly as a Trx-fusion protein in Escherichia coli, purified using immobilized metal affinity chromatography and reverse-phase HPLC, and tested in vitro against Gram-positive and Gram-negative bacterial strains. Results Lucifensin was active against Staphylococcus carnosus, Streptococcus pyogenes and Streptococcus pneumoniae (MIC 2 mg/L), as well as Staphylococcus aureus (MIC 16 mg/L). The peptide did not show antimicrobial activity towards Gram-negative bacteria. The MIC of lucifensin for the methicillin-resistant S. aureus and glycopeptide-intermediate S. aureus isolates tested ranged from 8 to >128 mg/L. Conclusions The TAST results did not reveal any highly secreted compounds with putative antimicrobial activity, implying an alternative antimicrobial activity of MDT. Lucifensin showed antimicrobial activities comparable to other defensins and could have potential as a future drug candidate scaffold, for redesign for other applications besides the topical treatment of infected wounds.
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Affiliation(s)
- Anders S Andersen
- Department of Microbiological Surveillance and Research, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen S, Denmark
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Mygind PH, Fischer RL, Schnorr KM, Hansen MT, Sönksen CP, Ludvigsen S, Raventós D, Buskov S, Christensen B, De Maria L, Taboureau O, Yaver D, Elvig-Jørgensen SG, Sørensen MV, Christensen BE, Kjaerulff S, Frimodt-Moller N, Lehrer RI, Zasloff M, Kristensen HH. Plectasin is a peptide antibiotic with therapeutic potential from a saprophytic fungus. Nature 2005; 437:975-80. [PMID: 16222292 DOI: 10.1038/nature04051] [Citation(s) in RCA: 440] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2005] [Accepted: 07/20/2005] [Indexed: 01/08/2023]
Abstract
Animals and higher plants express endogenous peptide antibiotics called defensins. These small cysteine-rich peptides are active against bacteria, fungi and viruses. Here we describe plectasin-the first defensin to be isolated from a fungus, the saprophytic ascomycete Pseudoplectania nigrella. Plectasin has primary, secondary and tertiary structures that closely resemble those of defensins found in spiders, scorpions, dragonflies and mussels. Recombinant plectasin was produced at a very high, and commercially viable, yield and purity. In vitro, the recombinant peptide was especially active against Streptococcus pneumoniae, including strains resistant to conventional antibiotics. Plectasin showed extremely low toxicity in mice, and cured them of experimental peritonitis and pneumonia caused by S. pneumoniae as efficaciously as vancomycin and penicillin. These findings identify fungi as a novel source of antimicrobial defensins, and show the therapeutic potential of plectasin. They also suggest that the defensins of insects, molluscs and fungi arose from a common ancestral gene.
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Abstract
We constructed and tested a Cre-loxP recombination-mediated vector system termed pCrox for use in transgenic plants. In this system, treatment of Arabidopsis under inducing conditions mediates an excision event that removes an intervening piece of DNA between a promoter and the gene to be expressed. The system developed here uses a heat-shock-inducible Cre to excise a DNA fragment flanked by lox sites, thereby generating a constitutive GUS reporter gene under control of the CaMV 35S promoter. Heat-shock-mediated excision of several, independent lines resulted in varying degrees of recombination-mediated GUS activation. Induction was shown to be possible at essentially any stage of plant growth. This single vector system circumvents the need for genetic crosses required by other, dual recombinase vector systems. The pCrox system may prove particularly useful in instances where transgene over-expression, or under-expression by antisense, would otherwise affect embryo, seed or seedling viability.
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Affiliation(s)
- T Hoff
- Department of Plant Physiology, University of Copenhagen, Denmark
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Schnorr KM, Laloue M, Hirel B. Isolation of cDNAs encoding two purine biosynthetic enzymes of soybean and expression of the corresponding transcripts in roots and root nodules. Plant Mol Biol 1996; 32:751-7. [PMID: 8980527 DOI: 10.1007/bf00020216] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Soybean nodule cDNA clones encoding glycinamide ribonucleotide (GAR) synthetase (GMpurD) and GAR transformylase (GMpurN) were isolated by complementation of corresponding Escherichia coli mutants. GAR synthetase and GAR transformylase catalyse the second and the third steps in the de novo purine biosynthesis pathway, respectively. One class of GAR synthetase and three classes of GAR transformylase cDNA clones were identified. Northern blot analysis clearly shows that these purine biosynthetic genes are highly expressed in young and mature nodules but weakly expressed in roots and leaves. Expression levels of GMpurD and GMpurN mRNAs were not enhanced when ammonia was provided to non-nodulated roots.
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Affiliation(s)
- K M Schnorr
- Laboratoire de Biologie Cellulaire, INRA, Centre de Versailles, Versailles, France
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Schnorr KM, Gaillard C, Biget E, Nygaard P, Laloue M. A second form of adenine phosphoribosyltransferase in Arabidopsis thaliana with relative specificity towards cytokinins. Plant J 1996; 9:891-8. [PMID: 8696367 DOI: 10.1046/j.1365-313x.1996.9060891.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Adenine phosphoribosyltransferase (APRTase) is an important enzyme for its ability to convert adenine, a byproduct of many biochemical reactions, into AMP. By functional complementation of an Escherichia coli mutant, cDNAs encoding two APRTases have been cloned from Arabidopsis thaliana. One of the cDNAs (ATapt1) has been previously identified while the second (ATapt2) is of a previously unknown type. Kinetic analysis of the two enzymes purified from E. coli expressing the two cDNAs indicates that ATapt2 has a higher affinity for cytokinin than the ATapt1. RNase protection studies indicate that the ATapt2, is not expressed in leaves. Analysis of the gene structure indicates that ATapt2 has identical intron positions to ATapt1, but neither the intron sequence nor intron size are conserved between the two genes. The implications of a second, differentially expressed APRTase with affinity for both adenine and cytokinin are discussed.
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Affiliation(s)
- K M Schnorr
- Laboratoire de Biologie Cellulaire, INRA Institut National de Recherche Agronomique, Versailles, France
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Hoff T, Schnorr KM, Meyer C, Caboche M. Isolation of two Arabidopsis cDNAs involved in early steps of molybdenum cofactor biosynthesis by functional complementation of Escherichia coli mutants. J Biol Chem 1995; 270:6100-7. [PMID: 7890743 DOI: 10.1074/jbc.270.11.6100] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Most organisms appear to have a molybdenum cofactor consisting of a complex of molybdenum and a pterin derivative. Very little is known about molybdenum cofactor biosynthesis in plants or other eukaryotes, because the instability of the cofactor and its precursors makes it difficult to analyze this pathway. We have isolated two cDNA clones from the higher plant Arabidopsis thaliana encoding genes involved in early steps of molybdenum cofactor biosynthesis. The cDNAs were obtained by functional complementation of two Escherichia coli mutants deficient in single steps of molybdenum cofactor biosynthesis. The two cDNAs, designated Cnx2 and Cnx3, encode proteins of 43 and 30 kDa, respectively. They have significant identity to the E. coli genes, moaA and moaC, involved in molybdenum cofactor biosynthesis. Both genes have N-terminal extensions that resemble targeting signals for the chloroplasts or the mitochondria. Import studies with the translated proteins and purified mitochondria and chloroplasts did not show import of these proteins to either of these organelles. Northern analysis show that Cnx2 is expressed in all organs and strongest in roots. Cnx3 is not expressed in abundant levels in any tissue but roots. For both genes there is no detectable difference in the expression level from plants grown with nitrate or with ammonium. The Cnx2 gene has been mapped to chromosome II. Southern analysis suggests that both genes exist as single copies in the genome.
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Affiliation(s)
- T Hoff
- Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, Versailles, France
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Abstract
Glycinamide ribonucleotide (GAR) synthetase, GAR transformylase and aminoimidazole ribonucleotide (AIR) synthetase are the second, third and fifth enzymes in the 10-step de novo purine biosynthetic pathway. From a cDNA library of Arabidopsis thaliana, cDNAs encoding the above three enzymes were cloned by functional complementation of corresponding Escherichia coli mutants. Each of the cDNAs encode peptides comprising the complete enzymatic domain of either GAR synthetase, GAR transformylase or AIR synthetase. Comparisons of the three Arabidopsis purine biosynthetic enzymes with corresponding enzymes/polypeptide-fragments from procaryotic and eucaryotic sources indicate a high degree of conserved homology at the amino acid level, in particular with procaryotic enzymes. Assays from extracts of E. coli expressing the complementing clones verified the specific enzymatic activity of Arabidopsis GAR synthetase and GAR transformylase. Sequence analysis, as well as Northern blot analysis indicate that Arabidopsis has single and monofunctional enzymes. In this respect the organization of these three plant purine biosynthesis genes is fundamentally different from the multifunctional purine biosynthesis enzymes characteristic of other eucaryotes and instead resembles the one gene, one enzyme relationship found in procaryotes.
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Affiliation(s)
- K M Schnorr
- Laboratoire de Biologie Cellulaire, INRA, Centre de Recherches de Versailles, France
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Miyazaki J, Juricek M, Angelis K, Schnorr KM, Kleinhofs A, Warner RL. Characterization and sequence of a novel nitrate reductase from barley. Mol Gen Genet 1991; 228:329-34. [PMID: 1896007 DOI: 10.1007/bf00260624] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Barley (Hordeum vulgare L.) has both NADH-specific and NAD(P)H-bispecific nitrate reductases. Genomic and cDNA clones of the NADH nitrate reductase have been sequenced. In this study, a genomic clone (pMJ4.1) of a second type of nitrate reductase was isolated from barley by homology to a partial-length NADH nitrate reductase cDNA and the sequence determined. The open reading frame encodes a polypeptide of 891 amino acids and its interrupted by two small introns. The deduced amino acid sequence has 70% identity to the barley NADH-specific nitrate reductase. The non-coding regions of the pMJ4.1 gene have low homology (ca. 40%) to the corresponding regions of the NADH nitrate reductase gene. Expression of the pMJ4.1 nitrate reductase gene is induced by nitrate in root tissues which corresponds to the induction of NAD(P)H nitrate reductase activity. The pMJ4.1 nitrate reductase gene is sufficiently different from all previously reported higher plant nitrate reductase genes to suggest that it encodes the barley NAD(P)H-bispecific nitrate reductase.
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Affiliation(s)
- J Miyazaki
- Department of Crop and Soil Sciences, Washington State University, Pullman 99164-6420
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Abstract
Barley nitrate reductase cDNA and genomic clones were isolated by homology with the barley nitrate reductase cDNA clone bNRp10 and sequenced. This is the first reported analysis of a full-length nitrate reductase gene and its corresponding cDNA in the same species. The longest cDNA clone extends to within 9 bp of the ATG start codon and the sequence is similar to that reported for the higher plant NR sequences. As expected, the amino acid sequence of barley nitrate reductase is more related closely to the rice (84% homology) than to the Arabidopsis (62%) sequence. Four different polyA addition sites were identified from sequence analysis of nine barley NR cDNA clones. A 7.3 kb region of a genomic recombinant lambda clone was subcloned as two contiguous BamHI fragments into p Bluescript, designated pMJ7 and pMJ8, and sequenced. These clones include the entire nitrate reductase coding region, one large intron, 2.7 kb of untranslated sequence 5' to the translation start codon and 0.25 kb 3' to the translation termination codon. The mRNA cap site was identified as a cytosine, 111 bases upstream of the ATG translation start codon. The putative CAAT and TATA boxes were identified at -115 and -33 bp, respectively, with the mRNA cap site designated as +1. The barley nitrate reductase gene coding region strongly favors G or C in the third codon position.
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Affiliation(s)
- K M Schnorr
- Dept. of Crop and Soil Sciences, Washington State University, Pullman 99164-6420
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