Zinc-binding properties in Junín virus nucleocapsid protein

TORTORICI, M.A.; GHIRINGHELLI, P.D.; LOZANO, M.E.; ALBARIÑO, C.G.; ROMANOWSKI, V.

JOURNAL OF GENERAL VIROLOGY

SOC GENERAL MICROBIOLOGY

Lugar: Londres; Año: 2001 vol. 82 p. 121 - 128

0022-1317

The arenavirus nucleocapsid protein (N) is a highly basic 63 kDa protein with a dual function during the virus life-cycle. First, it is involved in essential steps of genome replication, promoting the synthesis of the full-length antigenomic copy of S RNA, and second it associates with the genomic RNA to form the nucleocapsid. We have expressed the N protein of Junín virus in E. coli and shown that it binds zinc in vitro. This property is in agreement with the presence in the carboxy-terminal region of the N protein of the CX(2)HX(23)CX(4)C sequence, which resembles a classical zinc-finger motif. The specificity for zinc binding was demonstrated by competition with other divalent metal ions. The ability of the predicted motif to bind zinc was established by analysis of a series of N mutants, including truncated variants and amino acid substitutions. In addition, alternative zinc-binding sites were found.