20597
All together , we provide in vivo evidence that PNPase and RNase R are indispensable in controlling tRNA ( Cys ) quality in the presence of mercury .
 Chemical: Cys; Chemical: mercury
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: Cys; Chemical: mercury