Linked Life Data

3294421

Source:http://linkedlifedata.com/resource/pubmed/id/3294421

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-9-2
pubmed:abstractText
MalF is an essential cytoplasmic membrane protein of the maltose transport system of Escherichia coli. We have developed a general approach for analysis of the mechanism of integration of membrane proteins and their membrane topology by characterizing a series of fusions of beta-galactosidase to MalF. The properties of the fusion proteins indicate the following. (1) The first two presumed transmembrane segments of MalF are sufficient to anchor beta-galactosidase firmly to the inner membrane. (2) Hybrid proteins with beta-galactosidase fused to a presumed cytoplasmic domain of MalF have high beta-galactosidase specific activity; fusions to periplasmic domains have low activity. We propose therefore, that periplasmic and cytoplasmic domains of integral membrane proteins can be distinguished by the enzymatic properties of such hybrid proteins. In general, it appears that cleaved or non-cleaved signal sequences when attached to beta-galactosidase cause it to become embedded in the membrane, and this results in the inability of the hybrid proteins to assemble into active enzyme. Additional properties of these fusion proteins contribute to our understanding of the regulation of MalF synthesis. The MalF protein, synthesized as part of the malEFG operon of E. coli, is approximately 30-fold less abundant in the cell than MalE protein (the maltose-binding protein). Differential amounts of the fusion proteins indicate that a regulatory signal occurs within the malF gene that is responsible for the step-down in expression from the malE gene to the malF gene.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ATP-Binding Cassette Transporters, http://linkedlifedata.com/resource/pubmed/chemical/Bacterial Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/MalE protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/Maltose-Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Monosaccharide Transport Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Periplasmic Binding Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/maltose transport system, E coli
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
200
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
501-11
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Genetic analysis of the membrane insertion and topology of MalF, a cytoplasmic membrane protein of Escherichia coli.
pubmed:affiliation
Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't