New Cyt-like δ-endotoxins from Dickeya dadantii: structure and aphicidal activity.
In the track of new biopesticides, four genes namely cytA, cytB, cytC and cytD encoding proteins homologous to Bacillus thuringiensis (Bt) Cyt toxins have been identified in the plant pathogenic bacteria Dickeya dadantii genome. Here we show that three Cyt-like δ-endotoxins from D. dadantii (CytA, CytB and CytC) are toxic to the pathogen of the pea aphid Acyrthosiphon pisum in terms of both mortality and growth rate. The phylogenetic analysis of the comprehensive set of Cyt toxins available in genomic databases shows that the whole family is of limited taxonomic occurrence, though in quite diverse microbial taxa. From a structure-function perspective the 3D structure of CytC and its backbone dynamics in solution have been determined by NMR. CytC adopts a cytolysin fold, structurally classified as a Cyt2-like protein. Moreover, the identification of a putative lipid binding pocket in CytC structure, which has been probably maintained in most members of the Cyt-toxin family, could support the importance of this lipid binding cavity for the mechanism of action of the whole family. This integrative approach provided significant insights into the evolutionary and functional history of D. dadantii Cyt toxins, which appears to be interesting leads for biopesticides.
Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, Orléans, F-45071, France.
Karine
K
Loth
1] INSA-Lyon, Villeurbanne F-69621, France [2] CNRS, UMR5240 MAP, Microbiologie Adaptation et Pathogénie, F-69622, France [3] Université Claude Bernard Lyon 1, F-69622, France [4] Université de Lyon, F-69000 Lyon, France.
Denis
D
Costechareyre
1] INSA-Lyon, Villeurbanne F-69621, France [2] CNRS, UMR5240 MAP, Microbiologie Adaptation et Pathogénie, F-69622, France [3] Université Claude Bernard Lyon 1, F-69622, France [4] Université de Lyon, F-69000 Lyon, France.
Géraldine
G
Effantin
1] INSA-Lyon, Villeurbanne F-69621, France [2] Université de Lyon, F-69000 Lyon, France [3] INRA, UMR203 BF2I, Biologie Fonctionnelle Insecte et Interaction, F-69621, France.
Yvan
Y
Rahbé
1] INSA-Lyon, Villeurbanne F-69621, France [2] CNRS, UMR5240 MAP, Microbiologie Adaptation et Pathogénie, F-69622, France [3] Université Claude Bernard Lyon 1, F-69622, France [4] Université de Lyon, F-69000 Lyon, France.
Guy
G
Condemine
Centre de Biophysique Moléculaire, CNRS UPR 4301, Université d'Orléans, Orléans, F-45071, France.
Céline
C
Landon
1] INSA-Lyon, Villeurbanne F-69621, France [2] Université de Lyon, F-69000 Lyon, France [3] INRA, UMR203 BF2I, Biologie Fonctionnelle Insecte et Interaction, F-69621, France.
Pedro
P
da Silva
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D004731:Endotoxins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004755:Enterobacteriaceae / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D019906:Nuclear Magnetic Resonance, Biomolecular; D010802:Phylogeny; D011487:Protein Conformation; D016415:Sequence Alignment; D012996:Solutions
D001426:Bacterial Proteins; D004731:Endotoxins; D012996:Solutions