Sequence alignment between 2ec6(B) and UniProt seq Q26069 (Q26069_PLAMG):

Q26069 (Q26069_PLAMG): Myosin regulatory light chain from Placopecten magellanicus
                 10        20        30        40        50        60        70        80        90       100       110       120       130       140       150       160  
         ---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+---------+--
UniProt: MADKERAQRATSNVFARLPQKLMQEMKEAFTMIDQNRDGFIDINDLKEMFSSLGRTPDDKELTAMLKEAPGPLNFTMFLSIFSDKLSGTDSEETIRNAFGMFDELDTKKLNIEYIKDLLENMGDNFNKDEMRMTFKEAPVEGGKFDYVRFVAMIKGSGDDDA
         ..................................XXX...........X........XXXX...........................................XX........................................................
PDB seq: ----------------------MQEMKEAFTMID---DGFIDINDLKEEFSSLGRTP----LTAMLKEAPGPLNFTMFLSIFSDKLSGTDSEETIRNAFGMFDEDATKKLNIEYIKDLLENMGDNFNKDEMRMTFKEAPVEGGKFDYVRFVAMIK-------
                               -------+----   --+---------+-------    --------+---------+---------+---------+---------+---------+---------+---------+---------+-----       
                                     30        40        50                  70        80        90       100       110       120       130       140       150