2IID

Structure of L-amino acid oxidase from Calloselasma rhodostoma in complex with L-phenylalanine

Summary for 2IID

• Entry DOI: 10.2210/pdb2iid/pdb
• Related: 1F8R
• Descriptor: L-amino-acid oxidase, alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose, ... (6 entities in total)
• Functional Keywords: flavoenzyme, fad binding domain, reaction mechanism, sustrate binding, oxidoreductase
• Biological source: Calloselasma rhodostoma (Malayan pit viper)
• Cellular location: Secreted: P81382
• Total number of polymer chains: 4
• Total formula weight: 231208.08

Authors

Moustafa, I.M.,Foster, S.,Lyubimov, A.Y.,Vrielink, A. (deposition date: 2006-09-27, release date: 2006-10-31, Last modification date: 2024-10-30)

Primary citation

Moustafa, I.M.,Foster, S.,Lyubimov, A.Y.,Vrielink, A.
Crystal Structure of LAAO from Calloselasma rhodostoma with an L-Phenylalanine Substrate: Insights into Structure and Mechanism
J.Mol.Biol., 364:991-1002, 2006

PubMed Abstract: L-Amino acid oxidase is a dimeric glycosylated flavoenzyme, a major constituent of the venom-from the snake Calloselasma rhodostoma. The enzyme exhibits apoptosis inducing effects as well as antibacterial and anti-HIV activities. The structure of l-amino acid oxidase with its substrate (L-phenylalanine) has been refined to a resolution of 1.8 A. The complex structure reveals the substrate bound to the reduced flavin (FADred). Alternative conformations for the key residues His223 and Arg322 are evident, suggesting a dynamic active site. Furthermore, conformational changes are apparent for the isoalloxazine ring; the three-ring system exhibits more bending around the N5-N10 axis compared to the oxidized flavin. The implications of the observed dynamics on the mechanism of catalysis are discussed. Inspection of buried surfaces in the enzyme reveals a Y-shaped channel system extending from the external surface of the protein to the active site. One portion of this channel may serve as the entry path for O2 during the oxidative half-reaction. The second region, separated from the proposed O2 channel by the N terminus (residues 8-16) of the protein, may play a role in H2O2 release. Interestingly, the latter portion of the channel would direct the H2O2 product to the exterior surface of the protein, near the glycan moiety, thought to anchor the enzyme to the host cell. This channel location may explain the ability of the enzyme to localize H2O2 to the targeted cell and thus induce the apoptotic effect.

PubMed: 17046020
DOI: 10.1016/j.jmb.2006.09.032

Experimental method

X-RAY DIFFRACTION (1.8 Å)