20662
We had previously reported the structure of an autoinhibited ZAP - 70 variant in which two regulatory tyrosine residues ( 315 and 319 ) in the SH2 - kinase linker were replaced by phenylalanine .
 Chemical: tyrosine; Chemical: phenylalanine
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: tyrosine; Chemical: phenylalanine