2535
The subunit - a gene is preceded by a gene coding for a small hydrophobic protein , as has been observed previously in the atp operons in E . coli , bacterium PS3 and cyanobacteria .
 subunit - a gene, atp operons
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 subunit - a gene, atp operons