Linked Life Data

21762677

Source:http://linkedlifedata.com/resource/pubmed/id/21762677

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2011-8-16
pubmed:abstractText
Shiga toxin (STx) belongs to the AB(5) toxin family and is transiently localized in the periplasm before secretion into the extracellular milieu. While producing outer membrane vesicles (OMVs) containing only A subunit of the toxin (STxA), we created specific STx1B- and STx2B-deficient mutants of E. coli O157:H7. Surprisingly, STxA subunit was absent in the OMVs and periplasm of the STxB-deficient mutants. In parallel, the A subunit of heat-labile toxin (LT) of enterotoxigenic E. coli (ETEC) was absent in the periplasm of the LT-B-deficient mutant, suggesting that instability of toxin A subunit in the absence of the B subunit is a common phenomenon in the AB(5) bacterial toxins. Moreover, STx2A was barely detectable in the periplasm of E. coli JM109 when stx2A was overexpressed alone, while it was stably present when stxB was co-expressed. Compared with STx2 holotoxin, purified STx2A was degraded rapidly by periplasmic proteases when assessed for in vitro proteolytic susceptibility, suggesting that the B subunit contributes to stability of the toxin A subunit in the periplasm. We propose a novel role for toxin B subunits of AB(5) toxins in protection of the A subunit from proteolysis during holotoxin assembly in the periplasm.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3002
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier B.V. All rights reserved.
pubmed:issnType
Print
pubmed:volume
1808
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2359-65
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Instability of toxin A subunit of AB(5) toxins in the bacterial periplasm caused by deficiency of their cognate B subunits.
pubmed:affiliation
The National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Ochang, Cheongwon, Chungbuk 363-883, Republic of Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't