10576
In this study we demonstrate that this bond is generated by the two [ 4Fe - 4S ] clusters containing radical SAM enzyme SkfB , which is encoded in the skf operon .
 Chemical: 4Fe - 4S; Chemical: SAM
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
 Entities: 4Fe - 4S, SAM 
Answer:
 Chemical: 4Fe - 4S; Chemical: SAM