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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
|
| pubmed:dateCreated |
1990-3-23
|
| pubmed:abstractText |
Comparative analyses of a number of secretory proteins processed by eukaryotic and prokaryotic signal peptidases have identified a strongly conserved feature regarding the residues positioned -3 and -1 relative to the cleavage site. These 2 residues of the signal peptide are thought to constitute a recognition site for the processing enzyme and are usually amino acids with small, neutral side chains. It was shown previously that the substitution of aspartic acid for alanine at -3 of the Escherichia coli maltose-binding protein (MBP) signal peptide blocked maturation by signal peptidase I but had no noticeable effect or MBP translocation across the cytoplasmic membrane of its biological activity. This identified an excellent system in which to undertake a detailed investigation of the structural requirements and limitations for the cleavage site. In vitro mutagenesis was used to generate 14 different amino acid substitutions at -3 and 13 different amino acid substitutions at -1 of the MBP signal peptide. The maturation of the mutant precursor species expressed in vivo was examined. Overall, the results obtained agreed fairly well with statistically derived models of signal peptidase I specificity, except that cysteine was found to permit efficient processing when present at either -3 and -1, and threonine at -1 resulted in inefficient processing. Interestingly, it was found that substitutions at -1 which blocked processing at the normal cleavage site redirected processing, with varying efficiencies, to an alternate site in the signal peptide represented by the Ala-X-Ala sequence at positions -5 to -3. The substitution of aspartic acid for alanine at -5 blocked processing at this alternate site but not the normal site. The amino acids occupying the -5 and -3 positions in many other prokaryotic signal peptides also have the potential for constituting alternate processing sites. This appears to represent another example of redundant information contained within the signal peptide.
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| pubmed:grant | |
| 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/Carrier Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Endopeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Maltose,
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/Oligonucleotide Probes,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Precursors,
http://linkedlifedata.com/resource/pubmed/chemical/Serine Endopeptidases,
http://linkedlifedata.com/resource/pubmed/chemical/maltose transport system, E coli,
http://linkedlifedata.com/resource/pubmed/chemical/type I signal peptidase
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Feb
|
| pubmed:issn |
0021-9258
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
25
|
| pubmed:volume |
265
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
3417-23
|
| pubmed:dateRevised |
2010-11-18
|
| pubmed:meshHeading |
pubmed-meshheading:2406254-ATP-Binding Cassette Transporters,
pubmed-meshheading:2406254-Amino Acid Sequence,
pubmed-meshheading:2406254-Base Sequence,
pubmed-meshheading:2406254-Carrier Proteins,
pubmed-meshheading:2406254-Endopeptidases,
pubmed-meshheading:2406254-Escherichia coli,
pubmed-meshheading:2406254-Escherichia coli Proteins,
pubmed-meshheading:2406254-Maltose,
pubmed-meshheading:2406254-Maltose-Binding Proteins,
pubmed-meshheading:2406254-Membrane Proteins,
pubmed-meshheading:2406254-Molecular Sequence Data,
pubmed-meshheading:2406254-Monosaccharide Transport Proteins,
pubmed-meshheading:2406254-Mutation,
pubmed-meshheading:2406254-Oligonucleotide Probes,
pubmed-meshheading:2406254-Protein Precursors,
pubmed-meshheading:2406254-Protein Processing, Post-Translational,
pubmed-meshheading:2406254-Serine Endopeptidases
|
| pubmed:year |
1990
|
| pubmed:articleTitle |
Maturation of Escherichia coli maltose-binding protein by signal peptidase I in vivo. Sequence requirements for efficient processing and demonstration of an alternate cleavage site.
|
| pubmed:affiliation |
Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill 27599-7290.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|