passages.id: split_6_test_3530_passage
passages.type: progene_text
passages.text: The first gene of the tagDEF operon encodes glycerol-3-phosphate cytidylyltransferase ( Pooley et al. , 1991 , Journal of General Microbiology 137 , 921-928 ) and its deduced product has significant homology with cholinephosphate cytidylyltransferase from yeast .