National Center for
3WA3: Crystal Structure of Copper Amine Oxidase From Arthrobacter Globiformis in N2 Condition
High-resolution crystal structure of copper amine oxidase from Arthrobacter globiformis: assignment of bound diatomic molecules as O2
Acta Crystallogr. D Biol. Crystallogr. (2013) 69 p.2483-2494
The crystal structure of a copper amine oxidase from Arthrobacter globiformis was determined at 1.08 A resolution with the use of low-molecular-weight polyethylene glycol (LMW PEG; average molecular weight approximately 200) as a cryoprotectant. The final crystallographic R factor and Rfree were 13.0 and 15.0%, respectively. Several molecules of LMW PEG were found to occupy cavities in the protein interior, including the active site, which resulted in a marked reduction in the overall B factor and consequently led to a subatomic resolution structure for a relatively large protein with a monomer molecular weight of approximately 70 000. About 40% of the presumed H atoms were observed as clear electron densities in the Fo - Fc difference map. Multiple minor conformers were also identified for many residues. Anisotropic displacement fluctuations were evaluated in the active site, which contains a post-translationally derived quinone cofactor and a Cu atom. Furthermore, diatomic molecules, most likely to be molecular oxygen, are bound to the protein, one of which is located in a region that had previously been proposed as an entry route for the dioxygen substrate from the central cavity of the dimer interface to the active site.