6763
Identification of this region as the E . coli tmk gene was confirmed by functional complementation of a yeast dTMP kinase temperature - sensitive mutant and by in vitro enzyme assay of the thymidylate kinase activity in cell extracts of E . coli by use of tmk - overproducing plasmids .
 E . coli tmk gene, yeast dTMP kinase, thymidylate kinase, tmk
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 E . coli tmk gene, yeast dTMP kinase, thymidylate kinase, tmk