Plasmodium falciparum apicoplast transit peptides are unstructured in vitro and during apicoplast import.

ABSTRACT: Trafficking of soluble proteins to the apicoplast in Plasmodium falciparum is determined by an N-terminal transit peptide (TP) which is necessary and sufficient for apicoplast import. Apicoplast precursor proteins are synthesized at the rough endoplasmic reticulum, but are then specifically sorted from other proteins in the secretory pathway. The mechanism of TP recognition is presently unknown. Apicoplast TPs do not contain a conserved sequence motif; therefore, we asked whether they contain an essential structural motif. Using nuclear magnetic resonance to study a model TP from acyl carrier protein, we found a short, low-occupancy helix, but the TP was otherwise disordered. Using an in vivo localization assay, we blocked TP secondary structure by proline mutagenesis, but found robust api

SUBMITTER: Gallagher JR 

PROVIDER: S-EPMC3629917 | biostudies-literature | 2011 Sep

REPOSITORIES: biostudies-literature