passages.id: split_5_test_2701_passage
passages.type: progene_text
passages.text: The ORFs were found to share significant homologies and to correspond closely in molecular mass to previously characterized arc genes ; thus , they were designated arcA ( AD ) , arcB ( ornithine carbamyltransferase ) , arcC ( carbamate kinase ) , arcD ( arginine - ornithine antiporter ) , arcT ( dipeptidase ) , and arcR ( regulator ) .