Linked Life Data

7914193

Source:http://linkedlifedata.com/resource/pubmed/id/7914193

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1994-9-8
pubmed:abstractText
Expression of eukaryotic polytopic membrane proteins in Escherichia coli could provide an invaluable system for structure-function studies. Recently, the functional expression of a mouse multidrug resistance protein (Mdr1) in E. coli was described (Bibi, E., Gros, P., and Kaback, H. R. (1993) Proc. Natl. Acad. Sci. U. S. A. 90, 9209-9213). In the present study, the phoA gene fusion approach has been utilized to determine the membrane topology of the N-terminal domain of Mdr. The results support the idea that the N-terminal half of Mdr contains six transmembrane helices (TMs). However, our observations suggest that the previously proposed TM4 (amino acid residues Thr214-Ala232) is located at the periplasmic face of the membrane. Alternatively, we propose that another stretch of amino acid residues (Leu243 (out) to Ile260 (in)) traverses the membrane. This assignment is indicated also by the following observations: 1) deletion of a segment containing the originally predicted TM4 (delta T214-K241) does not reverse the orientation of the Mdr-alkaline phosphatase hybrid that is located in the following cytoplasmic loop; 2) a "sandwich" chimera, in which alkaline phosphatase is inserted in-frame between amino acid residues Leu226 and Ser227, exhibits high alkaline phosphatase activity. The existence of an externally exposed hydrophobic domain in Mdr may have special structural and functional implications, and these may also be relevant to other members of the ABC superfamily.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
269
pubmed:geneSymbol
mdr1, phoA
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19910-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Membrane topology of multidrug resistance protein expressed in Escherichia coli. N-terminal domain.
pubmed:affiliation
Department of Biochemistry, Weizmann Institute of Science, Rehovot, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't