Linked Life Data

9003281

Source:http://linkedlifedata.com/resource/pubmed/id/9003281

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1997-2-12
pubmed:databankReference
pubmed:abstractText
Insecticidal CryI protoxins of Bacillus thuringiensis are activated by proteolysis in the midgut of insects. A conservation of proteolytic cleavage sites in the CryI proteins facilitates the expression of active toxins in transgenic plants to obtain protection from various insects. However, the engineering of CryIC toxins has, thus far, failed to yield applicable resistance to armyworms of Spodoptera species representing common insect pests worldwide. To improve the production of recombinant CryIC toxins, we established a CryIC consensus sequence by comparative analysis of three cryIC genes and tested the stability and protease sensitivity of truncated CryIC toxins in Escherichia coli and in vitro. In contrast to previous data, the boundaries of trypsin-resistant CryIC core toxin were mapped to amino acid residues I28 and R627. Proteolysis of the truncated CryIC proteins showed that Spodoptera midgut proteases may further shorten the C-terminus of CryIC toxin to residue A615. However, C-terminal truncation of CryIC to residue L614, and a mutation causing amino acid replacement I610T, abolished the insecticidal activity of CryIC toxin to S. littoralis larvae, as well as its resistance to trypsin and Spodoptera midgut proteases. Because no CryIC toxin carrying a proteolytically processed N-terminus could be stably expressed in bacteria, our data indicate that, in contrast to other CryI proteins, an entomocidal fragment located between amino acid positions 1 and 627 is required for stable production of recombinant CryIC toxins.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0026-8925
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
253
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
11-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9003281-Amino Acid Sequence, pubmed-meshheading:9003281-Animals, pubmed-meshheading:9003281-Bacillus thuringiensis, pubmed-meshheading:9003281-Bacterial Proteins, pubmed-meshheading:9003281-Bacterial Toxins, pubmed-meshheading:9003281-Cloning, Molecular, pubmed-meshheading:9003281-Consensus Sequence, pubmed-meshheading:9003281-Endopeptidases, pubmed-meshheading:9003281-Endotoxins, pubmed-meshheading:9003281-Genes, Bacterial, pubmed-meshheading:9003281-Hemolysin Proteins, pubmed-meshheading:9003281-Insecticides, pubmed-meshheading:9003281-Molecular Sequence Data, pubmed-meshheading:9003281-Mutation, pubmed-meshheading:9003281-Protein Processing, Post-Translational, pubmed-meshheading:9003281-Recombinant Proteins, pubmed-meshheading:9003281-Spodoptera, pubmed-meshheading:9003281-Trypsin
pubmed:year
1996
pubmed:articleTitle
Mapping of the entomocidal fragment of Spodoptera-specific Bacillus thuringiensis toxin CryIC.
pubmed:affiliation
Max-Planck Institut für Züchtungsforschung, Köln, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't