biostudies-literatureSudhamsu JNIGMS NIH HHS32968-76https://www.ebi.ac.uk/biostudies/studies/S-EPMC2583316biostudies-literatureUnknown283(47)AtNOS1/AtNOA1 was identified as a nitric oxide-generating enzyme in plants, but that function has recently been questioned. To resolve issues surrounding AtNOA1 activity, we report the biochemical properties and a 2.36 A resolution crystal structure of a bacterial AtNOA1 ortholog (YqeH). Geobacillus YqeH fused to a putative AtNOA1 leader peptide complements growth and morphological defects of Atnoa1 mutant plants. YqeH does not synthesize nitric oxide from L-arginine but rather hydrolyzes GTP. The YqeH structure reveals a circularly permuted GTPase domain and an unusual C-terminal beta-domain. A small N-terminal domain, disordered in the structure, binds zinc. Structural homology among the C-terminal domain, the RNA-binding regulator TRAP, and the hypoxia factor pVHL define a recognition mThe Journal of biological chemistryThe structure of YqeH. An AtNOS1/AtNOA1 ortholog that couples GTP hydrolysis to molecular recognition.PMC25833165R01GM067011Crane BRKlessig DFLee GISudhamsu JfalseThe structure of YqeH. An AtNOS1/AtNOA1 ortholog that couples GTP hydrolysis to molecular recognition.AtNOS1/AtNOA1 was identified as a nitric oxide-generating enzyme in plants, but that function has recently been questioned. To resolve issues surrounding AtNOA1 activity, we report the biochemical properties and a 2.36 A resolution crystal structure of a bacterial AtNOA1 ortholog (YqeH). Geobacillus YqeH fused to a putative AtNOA1 leader peptide complements growth and morphological defects of Atnoa1 mutant plants. YqeH does not synthesize nitric oxide from L-arginine but rather hydrolyzes GTP. The YqeH structure reveals a circularly permuted GTPase domain and an unusual C-terminal beta-domain. A small N-terminal domain, disordered in the structure, binds zinc. Structural homology among the C-terminal domain, the RNA-binding regulator TRAP, and the hypoxia factor pVHL define a recognition m2008-01-01T00:00:00Z2008 Nov2026-04-13T21:11:39.701Z2019-03-27T00:19:22ZS-EPMC25833161880174710.1074/jbc.m80483720010.1074/jbc.M804837200