Linked Life Data

1527014

Source:http://linkedlifedata.com/resource/pubmed/id/1527014

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
26
pubmed:dateCreated
1992-10-19
pubmed:databankReference
pubmed:abstractText
We have cloned a gene from a Salmonella typhimurium with the ability to complement the rfaC mutation (heptose-deficient lipopolysaccharide, sensitivity to rough-specific bacteriophages, and susceptibility to hydrophobic antibiotics). A 1018-base pair EcoRV-Tth111I fragment, subcloned into the pBluescriptKS+ vector to yield pKZ103, retains complementing activity. Nucleotide sequencing revealed an open reading frame corresponding to a protein of 317 amino acids (M(r) approximately 35,100). The plasmid pKZ103, which has a properly aligned T7 promoter, can overexpress a protein of M(r) = 31,000 when T7 RNA polymerase is supplied. An in vitro system was established for analysis of heptose addition to the precursor [4'-32P](KDO)2-IVA (Brozek, K. A., Hosaka, K., Robertson, A. D., and Raetz, C. R. H. (1989) J. Biol. Chem, 264, 6956-6966). Soluble fractions from wild-type or heptose-deficient rfa mutants were tested for their ability to convert [4'-32P](KDO)2-IVA to more polar substances. In wild-type extracts, these conversions required addition of ATP or ADP-heptose. In extracts of rfaC-, rfaD-, or rfaE-deficient strains, no polar products were observed with ATP. ADP-heptose restored synthesis in rfaD and rfaE but not rfaC extracts, indicating that rfaD and rfaE are involved in ADP-heptose formation. When the cloned rfaC gene was introduced into an rfaC-deficient mutant, extracts from such cells regained the ability to metabolize [4'-32P](KDO)2-IVA, showing that rfaC encodes the enzyme that attaches the proximal heptose to lipopolysaccharide.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:geneSymbol
rfaC, rfaD, rfaE, rfaF
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
18874-84
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
The rfaC gene of Salmonella typhimurium. Cloning, sequencing, and enzymatic function in heptose transfer to lipopolysaccharide.
pubmed:affiliation
Department of Biological Sciences, University of Calgary, Alberta, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't