_EC 6.5.1.- Ligases that form phosphoric-ester bonds. 81 PDB entries  
EC 6.-.-.- Ligases. [1,622 PDB entries]
EC 6.5.-.- Forming phosphoric ester bonds. [81 PDB entries]
EC 6.5.1.- Ligases that form phosphoric-ester bonds. [81 PDB entries]    
EC 6.5.1.1 Dna ligase (ATP). [39 PDB entries]
EC 6.5.1.2 Dna ligase (NAD(+)). [28 PDB entries]
EC 6.5.1.3 Rna ligase (ATP). [6 PDB entries]
EC 6.5.1.4 Rna 3'-terminal-phosphate cyclase (ATP). [8 PDB entries]
EC 6.5.1.5 Rna 3'-terminal-phosphate cyclase (GTP). [-]

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