PDBsum entry 1jn7

Transcription

PDB id: 1jn7

Contents

Protein chain

36 a.a.

Metals

_ZN

PDB id:

1jn7

Name:

Transcription

Title:

Solution structure of a cchh mutant of the ninth cchc zinc finger of u-shaped

Structure:

U-shaped transcriptional cofactor. Chain: a. Fragment: ninth zinc-finger domain. Engineered: yes. Mutation: yes

Source:

Drosophila melanogaster. Fruit fly. Organism_taxid: 7227. Gene: u-shaped. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

NMR struc:

20 models

Authors:

K.Kowalski,J.P.Mackay

Key ref:

K.Kowalski et al. (2002). Characterization of the conserved interaction between GATA and FOG family proteins. J Biol Chem, 277, 35720-35729. PubMed id: 12110675 DOI: 10.1074/jbc.M204663200

Date:

23-Jul-01 Release date: 25-Sep-02

Protein chain

Q9VPQ6  (USH_DROME) -  Zinc finger protein ush from Drosophila melanogaster

Seq: 1191 a.a.

Struc: 36 a.a.*

* PDB and UniProt seqs differ at 3 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.M204663200

J Biol Chem 277:35720-35729 (2002)

PubMed id: 12110675

Characterization of the conserved interaction between GATA and FOG family proteins.

K.Kowalski, C.K.Liew, J.M.Matthews, D.A.Gell, M.Crossley, J.P.Mackay.

ABSTRACT

The N-terminal zinc finger (ZnF) from GATA transcription factors mediates interactions with FOG family proteins. In FOG proteins, the interacting domains are also ZnFs; these domains are related to classical CCHH fingers but have an His --> Cys substitution at the final zinc-ligating position. Here we demonstrate that different CCHC fingers in the FOG family protein U-shaped contact the N-terminal ZnF of GATA-1 in the same fashion although with different affinities. We also show that these interactions are of moderate affinity, which is interesting given the presumed low concentrations of these proteins in the nucleus. Furthermore, we demonstrate that the variant CCHC topology enhances binding affinity, although the His --> Cys change is not essential for the formation of a stably folded domain. To ascertain the structural basis for the contribution of the CCHC arrangement, we have determined the structure of a CCHH mutant of finger nine from U-shaped. The structure is very similar overall to the wild-type domain, with subtle differences at the C terminus that result in loss of the interaction in vivo. Taken together, these results suggest that the CCHC zinc binding topology is required for the integrity of GATA-FOG interactions and that weak interactions can play important roles in vivo.

Selected figure(s)

Figure 1.
Fig. 1. The zinc finger domains of GATA-1 and U-shaped. A, schematic diagram of GATA-1. Zinc finger domains (NF and CF) are shown in black. B, schematic diagrams of FOG-1 and U-shaped. CCHH ZnFs are shown in gray, and CCHC ZnFs shown in black; ZnFs that can bind the GATA-1 NF are indicated with a star. C, ribbon diagram of the solution structure of USH-F9 (16). The extended region just before the fourth zinc ligand is indicated with a bracket. D, alignment of the amino acid sequences of murine FOG-1 and D. melanogaster U-shaped. Fingers that interact with GATA-1 NF contain a conserved motif. Residues essential for the interaction, judging from mutagenesis studies, are shown in a dotted box; residues that are important (but not essential) for the interaction are shown in a dashed box. Zinc ligands are underlined. The numbering from the native proteins is indicated beside the sequences, with the numbering system used in the text shown at the bottom.

Figure 6.
Fig. 6. Comparison of C32H with USH-F9. A, overlay of C32H and USH-F9, over the backbone atoms (C^ , C', N) of residues 9-29. USH-F9 is shown in dark gray, and C32H is shown in light gray. The two domains overlay with a root mean square difference of 0.5 Å over residues 9-29 of C32H and USH-F9. The two images are related by a rotation of 90° about a horizontal axis in the plane of the page. The effect of the Cys-32 His substitution on the conformation of Phe-30 and Tyr-31 is clearly visible. B, overlay of the zinc binding sites of C32H (light gray) and USH-F9 (dark gray). The two views are related by a 90° rotation about a horizontal axis in the plane of the page.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2002, 277, 35720-35729) copyright 2002.

Figures were selected by an automated process.