_EC 1.2.3.- With oxygen as acceptor. 18 PDB entries  
EC 1.-.-.- Oxidoreductases. [8,663 PDB entries]
EC 1.2.-.- Acting on the aldehyde or oxo group of donors. [499 PDB entries]
EC 1.2.3.- With oxygen as acceptor. [18 PDB entries]    
EC 1.2.3.1 Aldehyde oxidase. [2 PDB entries]
EC 1.2.3.2 Transferred entry: 1.17.3.2. [-]
EC 1.2.3.3 Pyruvate oxidase. [12 PDB entries]
EC 1.2.3.4 Oxalate oxidase. [4 PDB entries]
EC 1.2.3.5 Glyoxylate oxidase. [-]
EC 1.2.3.6 Pyruvate oxidase (CoA-acetylating). [-]
EC 1.2.3.7 Indole-3-acetaldehyde oxidase. [-]
EC 1.2.3.8 Pyridoxal oxidase. [-]
EC 1.2.3.9 Aryl-aldehyde oxidase. [-]
EC 1.2.3.10 Deleted entry. [-]
EC 1.2.3.11 Transferred entry: 1.2.3.1. [-]
EC 1.2.3.12 Transferred entry: 1.14.13.82. [-]
EC 1.2.3.13 4-hydroxyphenylpyruvate oxidase. [-]
EC 1.2.3.14 Abscisic-aldehyde oxidase. [-]

[-] signifies that there are no PDB entries for the given enzyme subclass