GO:0051538

Interacting selectively and non-covalently with a 3 iron, 4 sulfur (3Fe-4S) cluster; this cluster consists of three iron atoms, with the inorganic sulfur atoms found between the irons and acting as bridging ligands. It is essentially a 4Fe-4S cluster with one iron missing. [GOC:ai, PMID:15952888, Wikipedia:Iron-sulfur_cluster]