title: Group X aldehyde dehydrogenases of Pseudomonas aeruginosa PAO1 degrade hydrazones.
abstract: Hydrazones are natural and synthetic compounds containing a C=N-N moiety. Here we found that the opportunistic pathogen Pseudomonas aeruginosa PAO1 produced NAD(+)- or NADP(+)-dependent hydrazone dehydrogenase (HDH), which converts hydrazones to the corresponding hydrazides and acids rather than to the simple hydrolytic product aldehydes. Gene cloning indicated that the HDH is part of the group X aldehyde dehydrogenase (ALDH) family, which is distributed among bacteria, although the physiological roles of the ALDH family remain unknown. The PAO1 strain upregulated HDH in the presence of the hydrazone adipic acid bis(ethylidene hydrazide) (AEH). Gene disruption of the HDH-encoding hdhA (PA4022) decreased growth rates in culture medium containing AEH as the sole carbon source, and this effect was more obvious in the double gene disruption of hdhA and its orthologous exaC (PA1984), indicating that these genes are responsible for hydrazone utilization. Recombinant proteins of group X ALDHs from Escherichia coli, Paracoccus denitrificans, and Ochrobactrum anthropi also acted as HDHs in that they produced HDH activity in the cells and degraded hydrazones. These findings indicated the physiological roles of group X ALDHs in bacteria and showed that they comprise a distinct ALDH subfamily.
authors.affiliation: Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Taniyama
authors.forename: Hideomi
authors.initials: H
authors.lastname: Itoh
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takuwa
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Yajima
authors.forename: Masanori
authors.initials: M
authors.lastname: Toyofuku
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Nomura
authors.forename: Naoki
authors.initials: N
authors.lastname: Takaya
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D003067:Coenzymes / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D055786:Gene Knockout Techniques; D006835:Hydrazones / Q000378:metabolism*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D020621:Ochrobactrum anthropi / Q000201:enzymology / Q000235:genetics; D010231:Paracoccus denitrificans / Q000201:enzymology / Q000235:genetics; D011550:Pseudomonas aeruginosa / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D003067:Coenzymes; D003470:Culture Media; D006835:Hydrazones; D011994:Recombinant Proteins; D009243:NAD; D009249:NADP; D000444:Aldehyde Dehydrogenase