Sequence alignment between 9is4(K) and UniProt seq P18263 (PSBK_CHLRE):

P18263 (PSBK_CHLRE): Photosystem II reaction center protein K from Chlamydomonas reinhardtii 
                 10        20        30        40      
         ---------+---------+---------+---------+------
UniProt: MTTLALVLAKLPEAYAPFAPIVDVLPVIPVFFILLAFVWQAAVSFR
PDB seq: ---------KLPEAYAPFAPIVDVLPVIPVFFILLAFVWQAAVSFR
                  +---------+---------+---------+------
                 10        20        30        40