Viral nucleocapsid CCHC zinc finger domain (NC CCHC domain)

The viral nucleocapsid CCHC zinc finger domain is a highly conserved structural motif found in the nucleocapsid (NC) proteins of retroviruses, most notably the NCp7 protein of HIV-1 [1]. This domain is characterized by a Cys-X2-Cys-X4-His-X4-Cys (CCHC) sequence that coordinates a zinc ion, which is essential for maintaining the protein's three-dimensional structure and functional integrity [1, 2]. Biologically, these domains function as nucleic acid chaperones, playing a critical role in the packaging of the viral RNA genome into new virions and facilitating key steps of reverse transcription, such as strand transfer and primer removal [2, 3]. Because the CCHC motif is invariant across many viral strains and is indispensable for viral infectivity, it represents a high-priority target for the development of broad-spectrum antiviral agents [3, 4]. Therapeutic strategies often involve "zinc ejectors," which are electrophilic molecules that covalently modify the coordinating cysteine residues, causing the release of the zinc ion and subsequent unfolding of the protein [4]. However, the clinical development of such inhibitors faces significant challenges, particularly regarding the selectivity of these agents for viral versus host zinc finger proteins and the potential for systemic toxicity [1, 4].

Other names

CCHC zinc finger [1]Retroviral nucleocapsid zinc finger [2]NCp7 zinc finger domain [3]Zinc-binding motif [1]

Zinc ejection through covalent modification of coordinating cysteine residues, leading to protein unfolding and loss of function [4].