Novel topology of a zinc-binding domain from a protein involved in regulating early Xenopus development.
EMBO J
; 14(23): 5947-56, 1995 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-8846787
Xenopus nuclear factor XNF7, a maternally expressed protein, functions in patterning of the embryo. XNF7 contains a number of defined protein domains implicated in the regulation of some developmental processes. Among these is a tripartite motif comprising a zinc-binding RING finger and B-box domain next to a predicted alpha-helical coiled-coil domain. Interestingly, this motif is found in a variety of protein including several proto-oncoproteins. Here we describe the solution structure of the XNF7 B-box zinc-binding domain determined at physiological pH by 1H NMR methods. The B-box structure represents the first three-dimensional structure of this new motif and comprises a monomer have two beta-strands, two helical turns and three extended loop regions packed in a novel topology. The r.m.s. deviation for the best 18 structures is 1.15 A for backbone atoms and 1.94 A for all atoms. Structure calculations and biochemical data shows one zinc atom ligated in a Cys2-His2 tetrahedral arrangement. We have used mutant peptides to determine the metal ligation scheme which surprisingly shows that not all of the seven conserved cysteines/histidines in the B-box motif are involved in metal ligation. The B-box structure is not similar in tertiary fold to any other known zinc-binding motif.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosfoproteínas
/
Zinc
/
Proteínas Nucleares
/
Dedos de Zinc
/
Proteínas de Xenopus
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
EMBO J
Año:
1995
Tipo del documento:
Article
Pais de publicación:
Reino Unido