locus-tag	class	description
usur_30	PF01367	5'-3' exonuclease, C-terminal SAM fold
usur_30	PF02739	5'-3' exonuclease, N-terminal resolvase-like domain
usur_30	PF00476	DNA polymerase family A
usur_30	PF09281	Taq polymerase, exonuclease