5797
DtxR is an iron - dependent sequence - specific DNA - binding protein that binds to the tox operator , an inverted - repeat nucleotide sequence located upstream from the diphtheria toxin gene .
 DtxR, tox operator, diphtheria toxin gene
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 DtxR, tox operator, diphtheria toxin gene