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1  structure 9  species 2  interactions 68  sequences 5  architectures

Family: Endotoxin_mid (PF09131)

Summary: Bacillus thuringiensis delta-Endotoxin, middle domain

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

This is the Wikipedia entry entitled "Delta endotoxin". More...

Delta endotoxin Edit Wikipedia article

delta endotoxin, N-terminal domain
PDB 1ji6 EBI.jpg
crystal structure of the insecticidal bacterial del endotoxin Cry3Bb1 bacillus thuringiensis
Identifiers
Symbol Endotoxin_N
Pfam PF03945
InterPro IPR005639
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2
delta endotoxin
PDB 1dlc EBI.jpg
Structure of insecticidal delta-endotoxin from Bacillus thuringiensis.[1]
Identifiers
Symbol Endotoxin_M
Pfam PF00555
InterPro IPR015790
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2
OPM superfamily 95
OPM protein 1w99
Bacillus thuringiensis delta-Endotoxin, middle domain
PDB 1i5p EBI.jpg
insecticidal crystal protein cry2aa
Identifiers
Symbol Endotoxin_mid
Pfam PF09131
InterPro IPR015214
SCOP 1i5p
SUPERFAMILY 1i5p
delta endotoxin
PDB 1i5p EBI.jpg
insecticidal crystal protein cry2aa
Identifiers
Symbol Endotoxin_C
Pfam PF03944
Pfam clan CL0202
InterPro IPR005638
SCOP 1dlc
SUPERFAMILY 1dlc
TCDB 1.C.2

Delta endotoxins (δ-endotoxins, also called Cry and Cyt toxins) are pore-forming toxins produced by Bacillus thuringiensis species of bacteria. They are useful for their insecticidal action.

During spore formation the bacteria produce crystals of this protein. When an insect ingests these proteins, they are activated by proteolytic cleavage. The N-terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. The activated region of the delta toxin is composed of three distinct structural domains: an N-terminal helical bundle domain (IPR005639) involved in membrane insertion and pore formation; a beta-sheet central domain involved in receptor binding; and a C-terminal beta-sandwich domain (IPR005638) that interacts with the N-terminal domain to form a channel.[2][3][4][5]

References[edit]

  1. ^ Li JD, Carroll J, Ellar DJ (October 1991). "Crystal structure of insecticidal delta-endotoxin from Bacillus thuringiensis at 2.5 A resolution". Nature 353 (6347): 815–21. doi:10.1038/353815a0. PMID 1658659. 
  2. ^ Cygler M, Borisova S, Grochulski P, Masson L, Pusztai-carey M, Schwartz JL, Brousseau R (1995). "Bacillus thuringiensis CryIA(a) insecticidal toxin: crystal structure and channel formation". J. Mol. Biol. 254 (3): 447–464. doi:10.1006/jmbi.1995.0630. PMID 7490762. 
  3. ^ Ghosh D, Pangborn W, Galitsky N, Cody V, Wojtczak A, Luft JR, English L (2001). "Structure of the insecticidal bacterial delta-endotoxinCry3Bb1 of Bacillus thuringiensis". Acta Crystallogr. D 57 (8): 1101–1109. doi:10.1107/S0907444901008186. PMID 11468393. 
  4. ^ Grochulski P, Masson L, Borisova S, Pusztai-Carey M, Schwartz JL, Brousseau R, Cygler M (December 1995). "Bacillus thuringiensis CryIA(a) insecticidal toxin: crystal structure and channel formation". J. Mol. Biol. 254 (3): 447–64. doi:10.1006/jmbi.1995.0630. PMID 7490762. 
  5. ^ Galitsky N, Cody V, Wojtczak A, Ghosh D, Luft JR, Pangborn W, English L (August 2001). "Structure of the insecticidal bacterial delta-endotoxin Cry3Bb1 of Bacillus thuringiensis". Acta Crystallogr. D Biol. Crystallogr. 57 (Pt 8): 1101–9. doi:10.1107/S0907444901008186. PMID 11468393. 

Further reading[edit]

This article incorporates text from the public domain Pfam and InterPro IPR015790

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Bacillus thuringiensis delta-Endotoxin, middle domain Provide feedback

Members of this family adopt a structure consisting of three four-stranded beta-sheets, each with a Greek key fold, with internal pseudo threefold symmetry. Thus they act as a receptor binding beta-prism, binding to insect-specific receptors of gut epithelial cells [1].

Literature references

  1. Morse RJ, Yamamoto T, Stroud RM; , Structure. 2001;9:409-417.: Structure of Cry2Aa suggests an unexpected receptor binding epitope. PUBMED:11377201 EPMC:11377201


External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR015214

Many Bacillus species produce crystals of insecticidal toxins during spore formation. When an insect ingests these proteins, they are activated by proteolytic cleavage. The N terminus is cleaved in all of the proteins and a C-terminal extension is cleaved in some members. Once activated, the endotoxin binds to the gut epithelium and causes cell lysis by the formation of cation-selective channels, which leads to death. The activated region of the delta toxin is composed of three distinct structural domains: an N-terminal helical bundle domain (INTERPRO) involved in membrane insertion and pore formation; a beta-sheet central domain involved in receptor binding; and a C-terminal beta-sandwich domain (INTERPRO) that interacts with the N-terminal domain to form a channel [PUBMED:7490762, PUBMED:11468393].

This entry represents the central beta-sheet domain, which consistins of three four-stranded beta-sheets, each with a Greek key fold, with internal pseudo threefold symmetry. Thus, it acts as a receptor binding beta-prism, binding to insect-specific receptors of gut epithelial cells [PUBMED:11377201]. This entry is found almost exclusively in Bacillus thuringiensis.

Domain organisation

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Alignments

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  Seed
(3)
Full
(68)
Representative proteomes NCBI
(63)
Meta
(0)
RP15
(0)
RP35
(0)
RP55
(0)
RP75
(0)
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  Seed
(3)
Full
(68)
Representative proteomes NCBI
(63)
Meta
(0)
RP15
(0)
RP35
(0)
RP55
(0)
RP75
(0)
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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

External links

MyHits provides a collection of tools to handle multiple sequence alignments. For example, one can refine a seed alignment (sequence addition or removal, re-alignment or manual edition) and then search databases for remote homologs using HMMER3.

Pfam alignments:

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Trees

This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

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Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: pdb_1i5p
Previous IDs: none
Type: Domain
Author: Sammut SJ
Number in seed: 3
Number in full: 68
Average length of the domain: 192.60 aa
Average identity of full alignment: 70 %
Average coverage of the sequence by the domain: 32.83 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.2 21.2
Trusted cut-off 21.7 21.5
Noise cut-off 20.0 21.1
Model length: 206
Family (HMM) version: 5
Download: download the raw HMM for this family

Species distribution

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Interactions

There are 2 interactions for this family. More...

Endotoxin_N Endotoxin_C

Structures

For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Endotoxin_mid domain has been found. There are 1 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.

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