Structural and biophysical characterization of Bacillus thuringiensis insecticidal proteins Cry34Ab1 and Cry35Ab1.
Bacillus thuringiensis strains are well known for the production of insecticidal proteins upon sporulation and these proteins are deposited in parasporal crystalline inclusions. The majority of these insect-specific toxins exhibit three domains in the mature toxin sequence. However, other Cry toxins are structurally and evolutionarily unrelated to this three-domain family and little is known of their three dimensional structures, limiting our understanding of their mechanisms of action and our ability to engineer the proteins to enhance their function. Among the non-three domain Cry toxins, the Cry34Ab1 and Cry35Ab1 proteins from B. thuringiensis strain PS149B1 are required to act together to produce toxicity to the western corn rootworm (WCR) Diabrotica virgifera virgifera Le Conte via a pore forming mechanism of action. Cry34Ab1 is a protein of ∼14 kDa with features of the aegerolysin family (Pfam06355) of proteins that have known membrane disrupting activity, while Cry35Ab1 is a ∼44 kDa member of the toxin_10 family (Pfam05431) that includes other insecticidal proteins such as the binary toxin BinA/BinB. The Cry34Ab1/Cry35Ab1 proteins represent an important seed trait technology having been developed as insect resistance traits in commercialized corn hybrids for control of WCR. The structures of Cry34Ab1 and Cry35Ab1 have been elucidated to 2.15 Å and 1.80 Å resolution, respectively. The solution structures of the toxins were further studied by small angle X-ray scattering and native electrospray ion mobility mass spectrometry. We present here the first published structure from the aegerolysin protein domain family and the structural comparisons of Cry34Ab1 and Cry35Ab1 with other pore forming toxins.
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Matthew S
MS
Kelker
Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom.
Colin
C
Berry
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Steven L
SL
Evans
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Reetal
R
Pai
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
David G
DG
McCaskill
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Nick X
NX
Wang
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Joshua C
JC
Russell
Cardiff School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom.
Matthew D
MD
Baker
Rigaku Americas Corporation, The Woodlands, Texas, United States of America.
Cheng
C
Yang
Rigaku Americas Corporation, The Woodlands, Texas, United States of America.
J W
JW
Pflugrath
School of Optometry & Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom.
Matthew
M
Wade
School of Optometry & Vision Sciences, Cardiff University, Cardiff, Wales, United Kingdom.
Tim J
TJ
Wess
Dow AgroSciences, LLC, Indianapolis, Indiana, United States of America.
Kenneth E
KE
Narva
D001413:Bacillus thuringiensis / Q000737:chemistry* / Q000378:metabolism; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D018360:Crystallography, X-Ray; D004731:Endotoxins / Q000737:chemistry* / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics; D015870:Gene Expression; D006460:Hemolysin Proteins / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011551:Pseudomonas fluorescens / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D005656:Fungal Proteins; D006460:Hemolysin Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; C461279:aegerolysin; C030956:insecticidal crystal protein, Bacillus Thuringiensis