Crystal structure determinations of oxidized and reduced pseudoazurins from Achromobacter cycloclastes. Concerted movement of copper site in redox forms with the rearrangement of hydrogen bond at a remote histidine.Inoue, T., Nishio, N., Suzuki, S., Kataoka, K., Kohzuma, T., Kai, Y.
(1999) J.Biol.Chem. 274: 17845-17852
- PubMed: 10364229
- Primary Citation of Related Structures:
- PubMed Abstract:
- Crystallization and Preliminary X-Ray Studies on Pseudoazurin from Achromobacter Cycloclastes Iam1013
Inoue, T.,Nishio, N.,Kai, Y.,Harada, S.,Ohshiro, Y.,Suzuki, S.,Kohzuma, T.,Shidara, S.,Iwasaki, H.
(1993) J.Biochem.(Tokyo) 114: 761
The crystal structures of oxidized and reduced pseudoazurins from a denitrifying bacterium, Achromobacter cycloclastes IAM1013, have been determined at 1.35- and 1.6-A resolutions, respectively. The copper site in the oxidized state exhibits a distor ...
The crystal structures of oxidized and reduced pseudoazurins from a denitrifying bacterium, Achromobacter cycloclastes IAM1013, have been determined at 1.35- and 1.6-A resolutions, respectively. The copper site in the oxidized state exhibits a distorted tetrahedral structure like those of other pseudoazurins. However, not only a small change of the copper geometry, but concerted peptide bond flips are identified. The imidazole ring of remote His6 has a hydrogen bonding distance of 2.73 A between N-delta1(His6) and O-gamma1(Thr36) in the oxidized protein. When the protein is reduced at pH 6.0, the imidazole ring rotates by 30.3 degrees and moves 1.00 A away from the position of the oxidized state. A new hydrogen bond between N-epsilon2(His6) and O-epsilon1(Glu4) is formed with a distance of 3.03 A, while the hydrogen bond between N-delta1(His6)-O-gamma1(Thr36) is maintained with an interatomic distance of 2.81 A. A concomitant peptide bond flip of main chain between Ile34 and Thr36 occurs.
Department of Materials Chemistry, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871, Japan.