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Three missense mutants in subunit a of the Escherichia coli F1F0 - ATPase were isolated and characterized after hydroxylamine mutagenesis of a plasmid carrying the uncB ( subunit a ) gene .
 Escherichia coli F1F0 - ATPase, uncB ( subunit a ) gene
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 Escherichia coli F1F0 - ATPase, uncB ( subunit a ) gene