scholarly journals Structural and Functional Insights into the C-terminal Fragment of Insecticidal Vip3A Toxin of Bacillus thuringiensis

Toxins ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 438
Author(s):  
Kun Jiang ◽  
Yan Zhang ◽  
Zhe Chen ◽  
Dalei Wu ◽  
Jun Cai ◽  
...  

The vegetative insecticidal proteins (Vips) secreted by Bacillus thuringiensis are regarded as the new generation of insecticidal toxins because they have different insecticidal properties compared with commonly applied insecticidal crystal proteins (Cry toxins). Vip3A toxin, representing the vast majority of Vips, has been used commercially in transgenic crops and bio-insecticides. However, the lack of both structural information on Vip3A and a clear understanding of its insecticidal mechanism at the molecular level limits its further development and broader application. Here we present the first crystal structure of the C-terminal fragment of Vip3A toxin (Vip3Aa11200–789). Since all members of this insecticidal protein family are highly conserved, the structure of Vip3A provides unique insight into the general domain architecture and protein fold of the Vip3A family of insecticidal toxins. Our structural analysis reveals a four-domain organization, featuring a potential membrane insertion region, a receptor binding domain, and two potential glycan binding domains of Vip3A. In addition, cytotoxicity assays and insect bioassays show that the purified C-terminal fragment of Vip3Aa toxin alone have no insecticidal activity. Taken together, these findings provide insights into the mode of action of the Vip3A family of insecticidal toxins and will boost the development of Vip3A into more efficient bio-insecticides.

Author(s):  
Kun Jiang ◽  
Yan Zhang ◽  
Zhe Chen ◽  
Dalei Wu ◽  
Jun Cai ◽  
...  

AbstractThe vegetative insecticidal proteins (Vips) secreted by Bacillus thuringiensis are regarded as the new generation of insecticidal toxins because they have different insecticidal properties compared with commonly applied insecticidal crystal proteins (Cry toxins). Vip3A toxin, representing the vast majority of Vips, has been used commercially in transgenic crops and bio-insecticides. However, the lack of both structural information of Vip3A and a clear understanding of its insecticidal mechanism at the molecular level, limits its further development and broader application. Here we present the first crystal structure of the Vip3A toxin in an activated form. Since all members of this insecticidal protein family are highly conserved, the structure of Vip3A provides unique insight into the general domain architecture and protein fold of the Vip3 family of insecticidal toxins. Our structural analysis reveals a four-domain organization, featuring a potential membrane insertion region, a receptor binding domain, and two glycan binding domains of activated Vip3A. We further identify the specific glycan moieties recognized by Vip3A through a glycan array screen. Taken together, these findings provide insights into the mode of action of Vip3 family of insecticidal toxins, and will boost the development of Vip3 into more efficient bio-insecticides.


2014 ◽  
Vol 42 (6) ◽  
pp. 4113-4122 ◽  
Author(s):  
Dmitrij Golovenko ◽  
Elena Manakova ◽  
Linas Zakrys ◽  
Mindaugas Zaremba ◽  
Giedrius Sasnauskas ◽  
...  

2019 ◽  
Vol 16 (2) ◽  
pp. 159-172 ◽  
Author(s):  
Elaheh Kashani-Amin ◽  
Ozra Tabatabaei-Malazy ◽  
Amirhossein Sakhteman ◽  
Bagher Larijani ◽  
Azadeh Ebrahim-Habibi

Background: Prediction of proteins’ secondary structure is one of the major steps in the generation of homology models. These models provide structural information which is used to design suitable ligands for potential medicinal targets. However, selecting a proper tool between multiple Secondary Structure Prediction (SSP) options is challenging. The current study is an insight into currently favored methods and tools, within various contexts. Objective: A systematic review was performed for a comprehensive access to recent (2013-2016) studies which used or recommended protein SSP tools. Methods: Three databases, Web of Science, PubMed and Scopus were systematically searched and 99 out of the 209 studies were finally found eligible to extract data. Results: Four categories of applications for 59 retrieved SSP tools were: (I) prediction of structural features of a given sequence, (II) evaluation of a method, (III) providing input for a new SSP method and (IV) integrating an SSP tool as a component for a program. PSIPRED was found to be the most popular tool in all four categories. JPred and tools utilizing PHD (Profile network from HeiDelberg) method occupied second and third places of popularity in categories I and II. JPred was only found in the two first categories, while PHD was present in three fields. Conclusion: This study provides a comprehensive insight into the recent usage of SSP tools which could be helpful for selecting a proper tool.


2018 ◽  
Vol 35 (2) ◽  
pp. 5-29
Author(s):  
JESRINA ANN XAVIER ◽  
EDMUND TERENCE GOMEZ

This article investigates changes in the conduct of ethnic enterprises followingthe emergence of a new generation of owners with varying class resources andas market conditions transform. The case study method is used to examinethe impact of changing class resources and market conditions on ethnicallybasedenterprises, exploring the effects of generational transitions among smallIndian owned companies in the food industry in Malaysia. The results providean insight into key changes in the evolution of Indian owned enterprises. Theyindicate that changes in class resources and market conditions have enabledIndian owned food-based companies to alter their products to fit a largermarket, while responding to the demands of a rapidly modernizing society.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2173
Author(s):  
Grace Gar-Lee Yue ◽  
Clara Bik-San Lau ◽  
Ping-Chung Leung

The immune modulating effects of selected herbs deserve careful studies to gain evidence-based support for their further development. We have been working hard on many items of medicinal herbs to gain insight into their immunomodulatory effects relevant to cancer treatment in particular, while infection control is not excluded. Nine of them have been selected to give the results of our exploration on their biological, particularly immunomodulatory activities. Since Hong Kong people especially favor one medicinal mushroom, viz. Coriolus versicolor, a number of clinical trials using Coriolus for cancer-related studies are included in this review. While immune modulation platforms are being built for relevant studies, a brief account on the research targets and related procedures are given.


Author(s):  
Michelle A. Pang ◽  
Carolyn C. Seepersad

The evaluation of design concepts is a time consuming and resource intensive process. Crowdsourcing evaluations has been examined in previous work as a means to reduce the need for expert raters, while achieving similar evaluation results. This paper examines the impact of empathically priming novice raters on their evaluation of alternative design concepts. The rating system is based on a pairwise comparison method that requires minimal training of novice raters. In a pilot study the pairwise method for crowdsourcing evaluations is compared with crowdsourced evaluations using non-pairwise rating scales and with the evaluations of expert raters. The primary study incorporates written and empathic priming strategies to determine their impact on novice raters’ evaluation of concepts. Raters are asked to consider several criteria, including novelty, feasibility, clarity (of the concept), usefulness, ease of use, and overall worthiness of further development. Results offer insight into the criteria that are most relevant to novice raters and whether empathic priming has a significant effect on those evaluations.


2006 ◽  
Vol 72 (3) ◽  
pp. 1771-1776 ◽  
Author(s):  
Claudia Stein ◽  
Gareth W. Jones ◽  
Tanya Chalmers ◽  
Colin Berry

ABSTRACT In Bacillus thuringiensis subsp. israelensis all of the insecticidal toxins are encoded on a single, large plasmid, pBtoxis. Sequencing of this plasmid revealed 125 potential coding sequences, many of which have predicted functions in gene regulation and physiological processes, such as germination. As a first step in understanding the possible role of pBtoxis in its host bacterium, a survey of the transcription of genes with predicted functions was carried out. Whereas many coding sequences, including those previously identified as probable pseudogenes, were not transcribed, mRNA was detected for 29 of the 40 sequences surveyed. Several of these sequences, including eight with similarities to the sequences of known transcriptional regulators, may influence wider gene regulation and thus may alter the phenotype of the host bacterium.


2006 ◽  
Vol 6 ◽  
pp. 992-997 ◽  
Author(s):  
Alison M. Kerr

More than 20 years of clinical and research experience with affected people in the British Isles has provided insight into particular challenges for therapists, educators, or parents wishing to facilitate learning and to support the development of skills in people with Rett syndrome. This paper considers the challenges in two groups: those due to constraints imposed by the disabilities associated with the disorder and those stemming from the opportunities, often masked by the disorder, allowing the development of skills that depend on less-affected areas of the brain. Because the disorder interferes with the synaptic links between neurones, the functions of the brain that are most dependent on complex neural networks are the most profoundly affected. These functions include speech, memory, learning, generation of ideas, and the planning of fine movements, especially those of the hands. In contrast, spontaneous emotional and hormonal responses appear relatively intact. Whereas failure to appreciate the physical limitations of the disease leads to frustration for therapist and client alike, a clear understanding of the better-preserved areas of competence offers avenues for real progress in learning, the building of satisfying relationships, and achievement of a quality of life.


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