TIC20 is a key component of the protein import machinery at the inner envelope membrane of chloroplasts. It is involved in protein precursor import into chloroplasts. The Arabidopsis genome encodes four Tic20 homologous proteins, AT1G04940(Tic20-I) , AT2G47840(Tic20-II) , AT4G03320(Tic20-IV) and AT5G55710(Tic20-V) .
