Involved in protein precursor import into chloroplasts. May be part of an intermediate translocation complex acting as a protein-conducting channel at the inner envelope. Part of the Tic complex. Component of the 1-MD complex, composed of TIC20-I, TIC214, TIC100 and TIC56. Interacts with the translocating preproteins. Hydrolysis of ATP is essential for the formation of this complex (PubMed:23372012). The 1-MD complex interacts with TIC21 (By similarity). Severe defects during embryogenesis, producing abnormal embryos and thereby leading to a lethality of young seedlings.