<p>This iron sulphur cluster is found at the N terminus of some proteins containing leucine-repeat variant (LRV) repeats (<db_xref db="INTERPRO" dbkey="IPR004830"/>). These proteins have a two-domain structure, composed of a small N-terminal domain containing a cluster of four Cys residues that houses the 4Fe:4S cluster, and a larger C-terminal domain containing the LRV repeats [<cite idref="PUB00003936"/>]. Biochemical studies revealed that the 4Fe:4S cluster is sensitive to oxygen, but does not appear to have reversible redox activity.</p>