Involved in the import of light-harvesting complex proteins (LHCP) and subsequent routing of these proteins to the chloroplast signal recognition particle (SRP) pathway. Interacts with CAO/cpSRP43, but is not a component of the transit complex. Interacts with LHCP (via T14 domain), TIC40 and TIC110. Highly expressed in leaves and seedlings. Detected in roots, but not in germinating seeds. Up-regulated by light. Not able to grow photoautotrophically in soil. Pale green, slow growth and no bolting. No appressed grana in chloroplasts.