9904
The results of these studies support a model in which VirB4 dimers or homomultimers contribute structural information for the assembly of a transenvelope channel competent for bidirectional DNA transfer , whereas an ATP - dependent activity is required for configuring this channel as a dedicated export machine .
 VirB4 dimers
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: GENE 
Text: {0} 
Answer:
 VirB4 dimers