6357
One such mutant also affects the overlapping - 10 hexamer of PR and results in reduced occupancy by both MerR and RNA polymerase , likely as a result of inefficient transcriptional initiation of merR mRNA .
 MerR, RNA polymerase, merR mRNA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 MerR, RNA polymerase, merR mRNA