SIGNAL SEQUENCES of AUTONOMOUS ORGANELLES  
ORGANELLE

SIGNAL...  TO

Description
MITOCHONDRIA mitoplasm a mitoplasmic-targeting signal sequence in proteins that is a short sequence @ N-terminal with + charged aa's (LYS & ARG). Signal sequence folds into a-helix with +'s on one side of helix
outer membrane a mitoplasmic-targeting sequence, followed by a stop transfer sequence that prevent entry through outer membrane porin channel
Inter-membrane space a mitoplasmic-targeting sequence, followed by a clevage site that results in release of protein into peri-mitochondrial space
Inner-membrane space a mitoplasmic-targeting sequence, with one of more transmembrane aa domain regions
CHLOROPLAST Chloroplasm contains  - an uncharged
a-helix with polar aa's along one side
  Outer membrane may be a  chloroplasm-targeting aa signal sequence and a stop transfer sequence ???
  Inter-membrane space may be a  chloroplasm-targeting aa signal sequence and a clevage site that releases protein into peri-chloroplast space ???