PSBR sequence alignment. Mature PSBR amino acid sequence alignment of PSBR in C. reinhardtii (Merchant et al., 2007), Volvox carteri (Prochnik et al., 2010), Chlorella variabilis (Blanc et al., 2010), Physcomitrella patens (Rensing et al., 2008), and Arabidopsis (Gil-Gómez et al., 1991) was performed using ClustalW (Larkin et al., 2007) and shaded with version 3.21 of BOXSHADE. Protein sequences were taken from the National Center for Biotechnology Information (reference sequences XP_001696588.1, XP_002945815.1, XP_005847921.1, XP_001760191.1, and NP_178025.1). Transit peptide cleavage sites were deduced by Emanuelsson et al. (2000) and PredAlgo (Tardif et al., 2012). Arrows indicate identified phosphorylation sites.