Members of the YidC/Oxa1/Alb3 protein family exhibit a wide phylogenetic distribution. They are found in the plasma membrane of bacteria, the inner membrane of mitochondria and the thylakoid membrane of chloroplasts, where they are involved in the biogenesis of membrane proteins. Detailed studies have demonstrated that members of the YidC/Oxa1/Alb3 family can interact with a variety of substrate proteins and perform versatile functions. Depending on the substrate protein, the YidC/Oxa1/Alb3 proteins can function as insertases or assist in folding and assembly of the proteins. This review focuses on Alb3 and its homologs in higher plants, green algae and cyanobacteria, and describes their role in the biogenesis of photosynthetic complexes.