2-amino-5-(5-aminopent-1-yn-1-yl)-7-{2-deoxy-5-O-[(S)-hydroxy{[(S)-hydroxy(phosphonooxy)phosphoryl]oxy}phosphoryl]-beta-D-erythro-pentofuranosyl}-3,7-dihydro-4H-pyrrolo[2,3-d]pyrimidin-4-one

P19821 — DNA polymerase I, thermostable