Chloroplast function requires the import of nuclear encoded proteins from the cytoplasm across the chloroplast double membrane. This is accomplished by two protein complexes, the Toc complex located at the outer membrane and the Tic complex located at the inner membrane. The Toc complex recognizes specific proteins by a cleavable N-terminal sequence and is primarily responsible for translocation through the outer membrane, while the Tic complex translocates the protein through the inner membrane. This entry represents Tic20, a core member of the Tic complex. This protein is deeply embedded in the inner envelope membrane and is thought to function as a protein- conducting component of the Tic complex.