Download MendeleyCrystallographic snapshots of iterative substrate translocations during nicotianamine synthesis in Archaea
Dreyfus, C., Lemaire, D., Mari, S., Pignol, D., Arnoux, P.(2009) Proc Natl Acad Sci U S A 106: 16180-16184
- PubMed: 19805277
- DOI: https://doi.org/10.1073/pnas.0904439106
- Primary Citation of Related Structures:
3FPE, 3FPF, 3FPG, 3FPH, 3FPJ - PubMed Abstract:
Nicotianamine (NA), a small molecule ubiquitous in plants, is an important divalent metal chelator and the main precursor of phytosiderophores. Nicotianamine synthase (NAS) is the enzyme catalyzing NA synthesis by the condensation of three aminopropyl moieties of S-adenosylmethionine (SAM) and the cyclization of one of them to form an azetidine ring. Here we report five crystal structures of an archaeal NAS from Methanothermobacter thermautotrophicus, either free or in complex with its product(s) and substrate(s). These structures reveal a two-domains fold arrangement of MtNAS, a small molecule related to NA (named here thermoNicotianamine or tNA), and an original mechanism of synthesis in a buried reaction chamber. This reaction chamber is open to the solvent through a small inlet, and a single active site allows the selective entrance of only one substrate at a time that is then processed and translocated stepwise.
Organizational Affiliation:
Laboratoire de Bioénergétique Cellulaire and Laboratoire des Interactions Protéine Métal, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institute of Environmental Biology and Biotechnology, Saint-Paul-lez-Durance, F-13108, France.
