Identification and Characterization of the Insecticidal Toxin “Makes Caterpillars Floppy” in Photorhabdus temperata M1021 Using a Cosmid Library

Toxins

Ihsan Ullah¹  Eun-Kyung Jang²  Min-Sung Kim¹  Jin-Ho Shin¹  Gun-Seok Park¹  Abdur Rahim Khan¹  Sung-Jun Hong¹  Byung-Kwon Jung¹  JungBae Choi¹  YeongJun Park¹  Yunyoung Kwak¹ 

[1] School of Applied Biosciences, College of Agriculture and Life Sciences, Kyungpook National University, Daegu 702-701, Korea; E-Mails:;Food and Biological Resources Examination Division, Korean Intellectual Property Office, Daejeon 302-701, Korea; E-Mail:

关键词: insecticidal toxin;    Galleria mellonella;    makes caterpillar floppy;    Photorhabdus temperata;    Tenebrio molitor;   

DOI  :  10.3390/toxins6072024

来源: mdpi

【 摘 要 】

Photorhabdus temperata is an entomopathogenic enterobacterium; it is a nematode symbiont that possesses pathogenicity islands involved in insect virulence. Herein, we constructed a P. temperata M1021 cosmid library in Escherichia coli XL1-Blue MRF` and obtained 7.14 × 10⁵ clones. However, only 1020 physiologically active clones were screened for insect virulence factors by injection of each E. coli cosmid clone into Galleria mellonella and Tenebrio molitorlarvae. A single cosmid clone, PtC1015, was consequently selected due to its characteristic virulent properties, e.g., loss of body turgor followed by death of larvae when the clone was injected into the hemocoel. The sequence alignment against the available sequences in Swiss-Prot and NCBI databases, confirmed the presence of the mcf gene homolog in the genome of P. temperata M1021 showing 85% homology and 98% query coverage with the P. luminescens counterpart. Furthermore, a 2932 amino acid long Mcf protein revealed limited similarity with three protein domains. The N-terminus of the Mcf encompassed consensus sequence for a BH3 domain, the central region revealed similarity to toxin B, and the C-terminus of Mcf revealed similarity to the bacterial export domain of ApxIVA, an RTX-like toxin. In short, the Mcf toxin is likely to play a role in the elimination of insect pests, making it a promising model for use in the agricultural field.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.