Participates with ALB4 in thylakoid protein targeting. May function with specific subset of thylakoidal proteins (PubMed:28684427). Binds to DNA and alters its conformation. May be involved in regulation of gene expression, nucleoid organization and DNA protection (By similarity). Homodimer. Interacts with ALB3 and ALB4. No visible macroscopic phenotype under normal growth condtions. Increased number of plastoglobules (lipid bodies) in chloroplasts. Belongs to the YbaB/EbfC family.