PDBsum entry: 1wsx

Apoptosis

PDB id: 1wsx

Contents

Protein chain

162 a.a. *

* Residue conservation analysis

PDB id:

1wsx

Name:

Apoptosis

Title:

Solution structure of mcl-1

Structure:

Myeloid cell leukemia sequence 1. Chain: a. Fragment: residues 152-308. Synonym: myeloid cell leukemia-1. Engineered: yes

Source:

Mus musculus. House mouse. Organism_taxid: 10090. Gene: mcl-1. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.

NMR struc:

20 models

Authors:

C.L.Day,L.Chen,S.J.Richardson,P.J.Harrison,D.C.Huang, M.G.Hinds

Key ref:

C.L.Day et al. (2005). Solution structure of prosurvival Mcl-1 and characterization of its binding by proapoptotic BH3-only ligands. J Biol Chem, 280, 4738-4744. PubMed id: 15550399 DOI: 10.1074/jbc.M411434200

Date:

12-Nov-04 Release date: 23-Nov-04

Protein chain

P97287  (MCL1_MOUSE) -  Induced myeloid leukemia cell differentiation protein Mcl-1 homolog

Seq: 331 a.a.

Struc: 162 a.a.*

* PDB and UniProt seqs differ at 4 residue positions (black crosses)

 Gene Ontology (GO) functional annotation 

• Biological process: regulation of apoptosis (1 term)

DOI no: 10.1074/jbc.M411434200

J Biol Chem 280:4738-4744 (2005)

PubMed id: 15550399

Solution structure of prosurvival Mcl-1 and characterization of its binding by proapoptotic BH3-only ligands.

C.L.Day, L.Chen, S.J.Richardson, P.J.Harrison, D.C.Huang, M.G.Hinds.

ABSTRACT

The B cell lymphoma-2 (Bcl-2) homologs myeloid cell leukemia-1 (Mcl-1) and A1 are prosurvival factors that selectively bind a subset of proapoptotic Bcl homology (BH) 3-only proteins. To investigate the molecular basis of the selectivity, we determined the solution structure of the C-terminal Bcl-2-like domain of Mcl-1. This domain shares features expected of a prosurvival Bcl-2 protein, having a helical fold centered on a core hydrophobic helix and a surface-exposed hydrophobic groove for binding its cognate partners. A number of residues in the binding groove differentiate Mcl-1 from its homologs, and in contrast to other Bcl-2 homologs, Mcl-1 has a binding groove in a conformation intermediate between the open structures characterized by peptide complexes and the closed state observed in unliganded structures. Mutagenesis of potential binding site residues was used to probe the contributions of groove residues to the binding properties of Mcl-1. Although mutations in Mcl-1 had little impact on binding, a single mutation in the BH3-only ligand Bad enabled it to bind both Mcl-1 and A1 while retaining its binding to Bcl-2, Bcl-xL, and Bcl-w. Elucidating the selective action of certain BH3-only ligands is required for delineating their mode of action and will aid the search for effective BH3-mimetic drugs.

Selected figure(s)

Figure 2.
FIG. 2. The BH3 binding activity is located in the Bcl-2 homology domain, and the C-terminal residues of this domain modulate ligand binding. A, immunoprecipitation of Mcl-1 variants from 293T cells. Equivalent 35S-labeled cell lysates from cells expressing FLAG-Mcl-1 variants and EE-Bim[EL] were immunoprecipitated using anti-FLAG M2 ( -F), anti-EE ( -E), or control anti-HA ( -H) monoclonal antibodies and fractionated on SDS-PAGE gels (left column). Western blots (middle and right columns) were performed with anti-Bim and anti-FLAG 9H1 antibodies. Mcl-1 degradation product is indicated by *. B, kinetic data for binding of BimBH3 peptide to Mcl-1 NC23 and Mcl-1 NC11. BimBH3 peptide was immobilized. C, Mcl-1 NC23 and Mcl-1 NC11 bind to the same proapoptotic proteins. The ability of the Mcl-1 proteins to bind to proapoptotic proteins was tested using GST pulldown experiments. Equivalent amounts of the GST fusion proteins were used in each experiment. Bound Mcl-1 was detected by Coomassie staining

Figure 4.
FIG. 4. Comparison of Mcl-1 and Bcl-x[L] binding grooves. A, Bcl-x[L] and Mcl-1 binding sites. Left and middle, unliganded Bcl-x[L] (PDB 1PQ0 [PDB] ) (39) and Bcl-x[L]-Bim complex with the Bim ligand removed (PDB 1PQ1 [PDB] ) (39) (respectively, ribbon residues: 90-159 and 191-196). Right, the equivalent residues (194-264 and 296-301) on Mcl-1. The orientation is the same as Fig. 3. Side chains displayed on Bcl-x[L]-Bim (middle) are those of residues that have atoms within 4 Å of a Bim atom on Bcl-x[L], and the analogous side chains are displayed on the other structures. The side chains are colored according to their proximity to a BH3-only residue (panel B). Pink represents residues close to the conserved Asp; those residues close to the conserved Leu of the BH3 domain are magenta. Cyan-, yellow-, and orange-colored residues surround the 3 hydrophobic residues at heptad positions 2d, 3d, and 4a, respectively (panel B). Other proximal residues are highlighted in blue. Bcl-x[L] Phe-97 has atoms within 4 Å of Ile-97 and Phe-101 of Bim. B, sequences of BH3 domains of mouse BH3-only proteins. The color scheme indicates key interactions consistent with those in panel A. Residues underlined in Bim and Bad are those that are helical in their Bcl-x[L] complexes (34, 39). The heptads are indicated.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2005, 280, 4738-4744) copyright 2005.

Figures were selected by an automated process.