원문정보
초록
영어
In Selenomonas ruminantium, strictly anaerobic and gram negative bacterium, cadaverine and putrescine, which are essential constituents of the peptidoglycan, are synthesized from L-lysine and L-ornithine by a constitutive lysine/ornithine decarboxylase (LDC/ODC). In here, firstly, we showed that S. ruminantium converted L-arginine into putrescine via agmatine. Secondary, we purified and characterized the arginine decarboxylase (ADC), the key enzyme in the agmatine pathway for a putrescine synthesis, and cloned the adc gene from S. ruminantium chromosomal DNA. ADC is comprised two identical monomeric subunits of 58 kDa. Both decarboxylation
activities were irreversibly inhibited by the DL-α-difluoromethylarginine but not DL-α- difluoromethyllysine nor the DL-α-difluoromethylornithine in a cell-free system. Finally, we identified and cloned the aguA and aguB genes, encoding the agmatine deiminase (AguA) and the N-carbamoyl-putrescine amidohydrolase (AguB) in a flanking region of the adc, both of which are involved in a conversion from agmatine into putrescine. Thus, we concluded that S. ruminantium has both ornithine and agmatine pathways for a synthesis of putrescine.