PDBsum entry 3ddt

Ligase

PDB id: 3ddt

Contents

Protein chains

48 a.a. *

44 a.a. *

Metals

_ZN ×6

Waters ×158

* Residue conservation analysis

PDB id:

3ddt

Name:

Ligase

Title:

Crystal structure of the b2 box from murf1 in dimeric state

Structure:

E3 ubiquitin-protein ligase trim63. Chain: a, b, c. Fragment: b2-box. Synonym: tripartite motif-containing protein 63, muscle-specific ring finger protein 1, murf1, murf-1, ring finger protein 28, striated muscle ring zinc finger protein, iris ring finger protein. Engineered: yes

Source:

Homo sapiens. Human. Organism_taxid: 9606. Expressed in: escherichia coli. Expression_system_taxid: 562.

Resolution:

1.90Å R-factor: 0.201 R-free: 0.252

Authors:

O.Mayans,M.Mrosek

Key ref:

M.Mrosek et al. (2008). Structural analysis of B-Box 2 from MuRF1: identification of a novel self-association pattern in a RING-like fold. Biochemistry, 47, 10722-10730. PubMed id: 18795805

Date:

06-Jun-08 Release date: 07-Oct-08

Protein chains

Q969Q1  (TRI63_HUMAN) -  E3 ubiquitin-protein ligase TRIM63 from Homo sapiens

Seq: 353 a.a.

Struc: 48 a.a.*

Protein chain

Q969Q1  (TRI63_HUMAN) -  E3 ubiquitin-protein ligase TRIM63 from Homo sapiens

Seq: 353 a.a.

Struc: 44 a.a.

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

Enzyme reactions

• Enzyme class: Chains A, B, C: E.C.2.3.2.27 - RING-type E3 ubiquitin transferase.
• Reaction: S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N₆- ubiquitinyl-[acceptor protein]-L-lysine

Biochemistry 47:10722-10730 (2008)

PubMed id: 18795805

Structural analysis of B-Box 2 from MuRF1: identification of a novel self-association pattern in a RING-like fold.

M.Mrosek, S.Meier, Z.Ucurum-Fotiadis, E.von Castelmur, E.Hedbom, A.Lustig, S.Grzesiek, D.Labeit, S.Labeit, O.Mayans.

ABSTRACT

The B-box motif is the defining feature of the TRIM family of proteins, characterized by a RING finger-B-box-coiled coil tripartite fold. We have elucidated the crystal structure of B-box 2 (B2) from MuRF1, a TRIM protein that supports a wide variety of protein interactions in the sarcomere and regulates the trophic state of striated muscle tissue. MuRF1 B2 coordinates two zinc ions through a cross-brace alpha/beta-topology typical of members of the RING finger superfamily. However, it self-associates into dimers with high affinity. The dimerization pattern is mediated by the helical component of this fold and is unique among RING-like folds. This B2 reveals a long shallow groove that encircles the C-terminal metal binding site ZnII and appears as the defining protein-protein interaction feature of this domain. A cluster of conserved hydrophobic residues in this groove and, in particular, a highly conserved aromatic residue (Y133 in MuRF1 B2) is likely to be central to this role. We expect these findings to aid the future exploration of the cellular function and therapeutic potential of MuRF1.