10572
Two [ 4Fe - 4S ] clusters containing radical SAM enzyme SkfB catalyze thioether bond formation during the maturation of the sporulation killing factor .
 Chemical: 4Fe - 4S; Chemical: thioether
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: 4Fe - 4S; Chemical: thioether