Net N-C charge imbalance may be important for signal sequence function in bacteria.
The net charge distribution in a region around the signal sequence cleavage site has been calculated for samples of 41 prokaryotic and 165 eukaryotic exported proteins. The results show that prokaryotic proteins in particular have a markedly higher incidence of acidic than of basic residues in this region. The possibility that a "dipolar" structure with a positive net charge difference between the N and C-terminal regions is important for signal sequence function in bacteria is suggested, and invoked to rationalize a number of known export-defective signal sequence mutations.
D000595:Amino Acid Sequence; D001419:Bacteria / Q000378:metabolism*; D005057:Eukaryotic Cells / Q000378:metabolism; D009154:Mutation; D011387:Prokaryotic Cells / Q000378:metabolism; D021382:Protein Sorting Signals / Q000378:metabolism*; D011993:Recombinant Fusion Proteins
D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins