TABLE 1.

Relationship between the charge of N-terminal amino acids and membrane destinations of lipoproteinsa

ProteinAmino acid at position:Presence in:
+1+2+3CMOM
LipL48CysLysGlu+
LipL41CysAlaAla++
LipL36CysLysSer+
LipL32CysGlyAla++
LipL31CysGlyAsp+
E. coli murein lipoproteinCysSerSer+
Inouye's mutantCysAspSer+
  • a LipL31 is the only leptospiral lipoprotein with a negatively charged amino acid in the +2 or +3 position after the N-terminal cysteine without a counterbalancing positively charged residue. LipL31 is the only leptospiral lipoprotein that is found exclusively in the cytoplasmic membrane (CM). Site-specific mutagenesis of the E. coli murein lipoprotein suggests that charged amino acids in this location function as a lipoprotein-sorting signal (42).