Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
52
pubmed:dateCreated
2002-12-23
pubmed:abstractText
Analysis of the precursors of bacterial exported proteins revealed that those having bulky hydrophobic residues at position -5 have a high incidence of Pro residues at positions -6 and -4, Val at position -3, and Ser at positions -4 and -2. This led to a hypothesis that the previously observed inhibition of processing by bulky residues at position -5 can be suppressed by introduction of Pro, Ser, or Val in the corresponding nearby positions. Subsequent mutational analysis of Escherichia coli alkaline phosphatase showed that, as it was predicted, Pro on either side of bulky hydrophobic -5 Leu, Ile, or Tyr completely restores efficiency of the maturation. Introduction of Val at position -3 also partially suppresses the inhibition imposed by -5 Leu, while a Ser residue at position -4 or -2 does not restore processing. In addition, effective maturation of a mutant with Pro residues at positions from -6 throughout -4 proved that polyproline conformation of this region is permissive for processing. To understand the effects of the mutations, we modeled a peptide substrate into the active site of the signal peptidase using the known position of the beta-lactam inhibitor. The inhibitory effect of the -5 residue and its suppression by either Pro -6 or Pro -4 can be explained if we assume that Pro-containing -6 to -4 regions adopt a polyproline conformation whereas the region without Pro residues has a beta-conformation. These results permit us to specify sequence requirements at -6, -5, and -4 positions for efficient processing and to improve the prediction of yet unknown cleavage sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
50396-402
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Processing of Escherichia coli alkaline phosphatase. Sequence requirements and possible conformations of the -6 to -4 region of the signal peptide.
pubmed:affiliation
Center for Molecular Modeling, CIT, National Institutes of Health, Bethesda, Maryland 20892, USA. kajava@crbm.cnrs-mop.fr
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't