Cry9 proteins show high insecticidal activity against different lepidopteran pests. Cry9 could be a valuable alternative to Cry1 proteins because it showed a synergistic effect with no cross-resistance. However, the pore-formation region of the Cry9 proteins is still unclear. In this study, nine mutations of certain Cry9Aa helices α3 and α4 residues resulted in a complete loss of insecticidal activity against the rice pest ; however, the protein stability and receptor binding ability of these mutants were not affected. Among these mutants, Cry9Aa-D121R, Cry9Aa-D125R, Cry9Aa-D163R, Cry9Aa-E165R, and Cry9Aa-D167R are unable to form oligomers in vitro, while the oligomers formed by Cry9Aa-R156D, Cry9Aa-R158D, and Cry9Aa-R160D are unstable and failed to insert into the membrane. These data confirmed that helices α3 and α4 of Cry9Aa are involved in oligomerization, membrane insertion, and toxicity. The knowledge of Cry9 pore-forming action may promote its application as an alternative to Cry1 insecticidal proteins.
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http://dx.doi.org/10.1021/acs.jafc.3c08070 | DOI Listing |
J Biol Chem
October 2018
From the Institute of Bio- and Geosciences, IBG-1: Biotechnology, Forschungszentrum Jülich, 52425 Jülich, Germany
Aerobic respiration in involves a cytochrome - supercomplex with a diheme cytochrome , which is the only -type cytochrome in this species. This organization is considered as typical for aerobic Actinobacteria. Whereas the biogenesis of heme-copper type oxidases like cytochrome has been studied extensively in α-proteobacteria, yeast, and mammals, nothing is known about this process in Actinobacteria.
View Article and Find Full Text PDFFEBS Lett
March 2012
Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, SE-106 91 Stockholm, Sweden.
The function of membrane-bound transporters is commonly affected by the milieu of the hydrophobic, membrane-spanning part of the transmembrane protein. Consequently, functional studies of these proteins often involve incorporation into a native-like bilayer where the lipid components of the membrane can be controlled. The classical approach is to reconstitute the purified protein into liposomes.
View Article and Find Full Text PDFJ Am Chem Soc
April 2004
Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7078, USA.
A novel platform for nucleic acid recognition that integrates the alpha-helix secondary structure of peptides with the codified base-pairing capability of nucleic acids is reported. The resulting alpha-helical peptide nucleic acids (alpha PNAs) are composed of a repeating tetrapeptidyl unit, aa(1)-aa(2)-aa(3)-Ser(B), where aa(1) through aa(3) represent generic ancillary amino acids and B = nucleobases linked to Ser via a methylene bridge. Effective syntheses of constituent Fmoc-protected nucleoamino acids (Fmoc-Ser(B)-OH, where B = thymine, cytosine, and uracil) are described along with a protocol for the solid-phase synthesis of 21mer alpha PNAs containing five such nucleobases.
View Article and Find Full Text PDFArch Microbiol
April 2001
Institut für Biotechnologie 1, Forschungszentrum Jülich GmbH, Germany.
In this work, the genes for cytochrome aa3 oxidase and the cytochrome bc1 complex in the gram-positive soil bacterium Corynebacterium glutamicum were identified. The monocistronic ctaD gene encoded a 65-kDa protein with all features typical for subunit I of cytochrome aa3 oxidases. A ctaD deletion mutant lacked the characteristic 600 nm peak in redox difference spectra, and growth in glucose minimal medium was strongly impaired.
View Article and Find Full Text PDFEur J Biochem
December 1996
Department of Microbial Physiology, Faculty of Biology, BioCentrum Amsterdam, Vrije Universiteit, The Netherlands.
The genes that encode the hc-type nitric-oxide reductase from Paracoccus denitrificans have been identified. They are part of a cluster of six genes (norCBQDEF) and are found near the gene cluster that encodes the cd1-type nitrite reductase, which was identified earlier [de Boer, A. P.
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