5678
Growth experiments using directed mutants confirmed the GAF phenotypes with Delta yggW ( putative haem - shuttling protein ) and Delta MCR _ 0457 ( hypothetical protein ) most severely attenuated during iron starvation , phenotypes which were restored upon genetic complementation of the deleted genes .
 Chemical: iron
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: iron