PDBsum entry 1a38

Complex (signal transduction/peptide)

PDB id: 1a38

Contents

Protein chains

216 a.a. *

Ligands

TRP-LEU-ASP-LEU-GLU ×2

* Residue conservation analysis

PDB id:

1a38

Name:

Complex (signal transduction/peptide)

Title:

14-3-3 protein zeta bound to r18 peptide

Structure:

14-3-3 protein zeta. Chain: a, b. Engineered: yes. R18 peptide (phcvprdlswldleanmclp). Chain: p, q. Engineered: yes

Source:

Bos taurus. Cattle. Organism_taxid: 9913. Expressed in: escherichia coli. Expression_system_taxid: 562.

Biol. unit:

Homo-Dimer (from PDB file)

Resolution:

3.35Å R-factor: 0.330 R-free: 0.390

Authors:

C.Petosa,S.C.Masters,J.Pohl,B.Wang,H.Fu,R.C.Liddington

Key ref:

C.Petosa et al. (1998). 14-3-3zeta binds a phosphorylated Raf peptide and an unphosphorylated peptide via its conserved amphipathic groove. J Biol Chem, 273, 16305-16310. PubMed id: 9632691 DOI: 10.1074/jbc.273.26.16305

Date:

28-Jan-98 Release date: 02-Mar-99

Protein chains

P63103  (1433Z_BOVIN) -  14-3-3 protein zeta/delta from Bos taurus

Seq: 245 a.a.

Struc: 216 a.a.

Enzyme reactions

• Enzyme class: E.C.?

DOI no: 10.1074/jbc.273.26.16305

J Biol Chem 273:16305-16310 (1998)

PubMed id: 9632691

14-3-3zeta binds a phosphorylated Raf peptide and an unphosphorylated peptide via its conserved amphipathic groove.

C.Petosa, S.C.Masters, L.A.Bankston, J.Pohl, B.Wang, H.Fu, R.C.Liddington.

ABSTRACT

14-3-3 proteins bind a variety of molecules involved in signal transduction, cell cycle regulation and apoptosis. 14-3-3 binds ligands such as Raf-1 kinase and Bad by recognizing the phosphorylated consensus motif, RSXpSXP, but must bind unphosphorylated ligands, such as glycoprotein Ib and Pseudomonas aeruginosa exoenzyme S, via a different motif. Here we report the crystal structures of the zeta isoform of 14-3-3 in complex with two peptide ligands: a Raf-derived phosphopeptide (pS-Raf-259, LSQRQRSTpSTPNVHMV) and an unphosphorylated peptide derived from phage display (R18, PHCVPRDLSWLDLEANMCLP) that inhibits binding of exoenzyme S and Raf-1. The two peptides bind within a conserved amphipathic groove on the surface of 14-3-3 at overlapping but distinct sites. The phosphoserine of pS-Raf-259 engages a cluster of basic residues (Lys49, Arg56, Arg60, and Arg127), whereas R18 binds via the amphipathic sequence, WLDLE, with its two acidic groups coordinating the same basic cluster. 14-3-3 is dimeric, and its two peptide-binding grooves are arranged in an antiparallel fashion, 30 A apart. The ability of each groove to bind different peptide motifs suggests how 14-3-3 can act in signal transduction by inducing either homodimer or heterodimer formation in its target proteins.

Selected figure(s)

Figure 1.
Fig. 1. Stereodiagram of the 14-3-3 monomer structure showing electron density for the pS-Raf-259 and R18 peptides. Helices forming the amphipathic groove are in white. In red is an F[o] F[c] map contoured at 2 calculated for crystals soaked in the a) pS-Raf-259 or b) R18 peptide. The maps are at 3.6 (A) and 3.35 Å (B) resolution using phases calculated from the protein model before inclusion of peptide atoms and improved by 4-fold noncrystallographic symmetry averaging, histogram matching, and solvent flattening in DM (25). The figure was produced with Bobscript (30) and Raster3D (31).

Figure 3.
Fig. 3. Amphipathicity and sequence conservation of the peptide-binding site. A, space-filling model of 14-3-3 with residues defining the amphipathic groove colored by side chain type: hydrophobic (green), polar (dark gray), acidic (red), and basic (blue). The pS-Raf-259 peptide backbone with its phosphoserine side chain is shown in yellow. Asp or Glu substitutions leading to reduced Raf binding3 (19) are marked with * (strong effect) or with ± (weak effect). B, the concave inner surface of 14-3-3 with residues invariant across 30 eukaryotic species in red (see also Table II). The R18 peptide is shown in green. None of the residues solvent-exposed on the rear, convex surface are invariant (not shown). C, close-up view of residues from helices 3, 5, 7, and 9 forming the amphipathic groove. All residues exposed in the groove are labeled except Gly53 and Gly169. The viewing orientation and coloring scheme are as in A. Residues boxed in solid or dashed lines correspond to those marked in A by * or ±, respectively. D, schematic of a 14-3-3 dimer with helices as cylinders showing bound Raf peptides with their phosphoserine side chains. The two peptides are oriented in an antiparallel fashion. The view is rotated by 90 ° around a horizontal axis compared with A-C, so that the dyad axis lies vertically in the plane of the page. The figure was produced with Molscript (32) and Raster3D (31).

The above figures are reprinted by permission from the ASBMB: J Biol Chem (1998, 273, 16305-16310) copyright 1998.

Figures were selected by an automated process.