PMID-sentid	Pub_year	Sent_text		comp_official_name	comp_offsetprotein_name	organism	prot_offset
12739977-4	2003	The significance of the ligands is that by placing a ligating side chain on a ring carbon (C-3), rather than on a ring nitrogen, the ring nitrogen not bound to the metal and its attached proton are available for hydrogen bonding.	Carbon	83-89	complement C3	Homo sapiens	91-94