10977
These results support the hypothesis that in the presence of tryptophan the ribosome translating tnaC blocks Rho ' s access to the boxA and rut sites , thereby preventing transcription termination .
 tnaC, Rho, boxA, rut sites
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 tnaC, Rho, boxA, rut sites