Linked Life Data

10564520

Source:http://linkedlifedata.com/resource/pubmed/id/10564520

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2000-1-19
pubmed:abstractText
We report a novel strategy for selecting mutations that mislocalize lipoproteins within the Escherichia coli cell envelope and describe the mutants obtained. A strain carrying a deletion of the chromosomal malE gene, coding for the periplasmic maltose-binding protein (MalE), cannot use maltose unless a wild-type copy of malE is present in trans. Replacement of the natural signal peptide of preMalE by the signal peptide and the first four amino acids of a cytoplasmic membrane-anchored lipoprotein resulted in N-terminal fatty acylation of MalE (lipoMalE) and anchoring to the periplasmic face of the cytoplasmic membrane, where it could still function. When the aspartate at position +2 of this protein was replaced by a serine, lipoMalE was sorted to the outer membrane, where it could not function. Chemical mutagenesis followed by selection for maltose-using mutants resulted in the identification of two classes of mutations. The single class I mutant carried a plasmid-borne mutation that replaced the serine at position +2 by phenylalanine. Systematic substitutions of the amino acid at position +2 revealed that, besides phenylalanine, tryptophan, tyrosine, glycine and proline could all replace classical cytoplasmic membrane lipoprotein sorting signal (aspartate +2). Analysis of known and putative lipoproteins encoded by the E. coli K-12 genome indicated that these amino acids are rarely found at position +2. In the class II mutants, a chromosomal mutation caused small and variable amounts of lipoMalE to remain associated with the cytoplasmic membrane. Similar amounts of another, endogenous outer membrane lipoprotein, NlpD, were also present in the cytoplasmic membrane in these mutants, indicating a minor, general defect in the sorting of outer membrane lipoproteins. Four representative class II mutants analysed were shown not to carry mutations in the lolA or lolB genes, known to be involved in the sorting of lipoproteins to the outer membrane.
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 Outer Membrane Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Fatty Acids, http://linkedlifedata.com/resource/pubmed/chemical/Lipoproteins, http://linkedlifedata.com/resource/pubmed/chemical/LolA protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/LolB protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/MalE protein, E coli, http://linkedlifedata.com/resource/pubmed/chemical/Maltose, http://linkedlifedata.com/resource/pubmed/chemical/Maltose-Binding 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/maltose transport system, E coli
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0950-382X
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
810-21
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Testing the '+2 rule' for lipoprotein sorting in the Escherichia coli cell envelope with a new genetic selection.
pubmed:affiliation
Unité de Génétique moléculaire, CNRS URA 1773, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't