6861
We demonstrate unknown facets of calnuc , which is a serine protease in which Ser - 378 of GXSXG motif , Asp - 328 of DTG motif , and His - 339 form the " catalytic triad , " locating the enzyme active site in the C - terminal region .
 serine, Ser, Asp, His, C
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 serine, Ser, Asp, His, C