Occurrence of agmatine pathway for putrescine synthesis in Selenomonas ruminatium.
Selenomonas ruminantium synthesizes cadaverine and putrescine from L-lysine and L-ornithine as the essential constituents of its peptidoglycan by a constitutive lysine/ornithine decarboxylase (LDC/ODC). S. ruminantium grew normally in the presence of the specific inhibitor for LDC/ODC, DL-alpha-difluoromethylornithine, when arginine was supplied in the medium. In this study, we discovered the presence of arginine decarboxylase (ADC), the key enzyme in agmatine pathway for putrescine synthesis, in S. ruminantium. We purified and characterized ADC and cloned its gene (adc) from S. ruminantium chromosomal DNA. ADC showed more than 60% identity with those of LDC/ODC/ADCs from Gram-positive bacteria, but no similarity to that from Gram-negative bacteria. In this study, we also cloned the aguA and aguB genes, encoding agmatine deiminase (AguA) and N-carbamoyl-putrescine amidohydrolase (AguB), both of which are involved in conversion from agmatine into putrescine. AguA and AguB were expressed in S. ruminantium. Hence, we concluded that S. ruminantium has both ornithine and agmatine pathways for the synthesis of putrescine.
Liao
Shaofu
S
Laboratory of Applied Microbiology, Department of Microbial Biotechnology, Graduate School of Agricultural Science, Tohoku University, Aobaku, Sendai 981-8555, Japan.
Poonpairoj
Phuntip
P
Ko
Kyong-Cheol
KC
Takatuska
Yumiko
Y
Yamaguchi
Yoshihiro
Y
Abe
Naoki
N
Kaneko
Jun
J
Kamio
Yoshiyuki
Y
D000376:Agmatine / Q000378:metabolism*; D000595:Amino Acid Sequence; D001120:Arginine / Q000378:metabolism; D001483:Base Sequence; D002262:Carboxy-Lyases / Q000378:metabolism; D017931:DNA Primers; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004795:Enzyme Stability; D008969:Molecular Sequence Data; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011700:Putrescine / Q000096:biosynthesis*; D020357:Selenomonas / Q000201:enzymology / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D017931:DNA Primers; D004791:Enzyme Inhibitors; D000376:Agmatine; D001120:Arginine; D002262:Carboxy-Lyases; D009955:Ornithine Decarboxylase; C021520:lysine decarboxylase; D011700:Putrescine