SLT/SLT-IIe(O139) protein (bs-0994P)

SLT/SLT-IIe(O139) protein

Quantity size:

100ug

MW:

N/AkDa

Source:

Natural protein

Form:

lyophilized powde

Purity:

،ف95% (Purified by HPLC)

Storage:

Shipped at 4،و, Store at -20،و (Avoid repeated freeze/thaw cycles).

Application:

Biological activity
Immunology research

Background:

Shiga-like toxin type II (SLT-II) and Shiga-like toxin type II variant (SLT-IIv) are cytotoxins produced by certain strains of Escherichia coli. Nucleotide sequence analyses had revealed that the structural genes for the A subunit and B subunit of SLT-II or SLT-IIv are arranged in an operon. Primer extension and S1 nuclease protection analyses identified a promoter for the slt-II operon 118 bases upstream of the slt-IIA gene. The slt-IIv promoter was demonstrated to be identical to the slt-II promoter. The slt-II and slt-IIv promoters differed significantly from the previously characterized Shiga toxin (stx) and Shiga-like toxin type 1 (slt-I) promoters. The transcriptional efficiencies of the stx and slt-II promoters were compared in fusions to the chloramphenicol acetyltransferase gene, and constitutive expression of the slt-II promoter was found to be equivalent to derepressed expression of the stx promoter. In contrast to the stx and slt-I promoters, the slt-II and slt-IIv promoters did not contain sequences for binding of the Fur repressor protein, and SLT-II production was not determined by iron levels in the media in various E. coli strains with wild-type or mutant ferric uptake regulation (fur) alleles. Northern (RNA) blot analysis demonstrated a single mRNA transcript for the slt-II operon, and further analysis of the slt-II operon by primer extension did not reveal an independent promoter for the B subunit gene. A putative rho-independent transcription terminator was identified 274 bases downstream of slt-IIB. These data indicated that the slt-II and slt-IIv operons differ from the stx/slt-I operon in regulation of their transcription by iron. Whether these regulatory differences enable the type I and type II groups of Shiga-like toxins to perform different roles in the pathogenesis of infectious diseases remains to be established.

Also known as:

SLT/SLT-IIe(O139) immunoaffinty purified full length proten; Shiga-Like Toxin Type II Variant protein, Immuno affinity chromatography purified.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.