This is The C-terminal helix I domain found in COP9 signalosome complex subunit 7a. The helix from CSN7 (helix I) contacts CSN6 helices I and II at the base of the bundle, nearest the PCI ring [1].

1: Crystal structure of the human COP9 signalosome. Lingaraju GM, Bunker RD, Cavadini S, Hess D, Hassiepen U, Renatus M, Fischer ES, Thoma NH; Nature. 2014;512:161-165. PMID:25043011