Figure 3.
Figure 3: Structure of the Cbl-N / ZAP-70 pY292 complex. a,
Stereo diagram showing an -carbon
trace of the complex. The bound ZAP-70 phosphopeptide is shown
in magenta. b, Stereo diagram showing the interactions with the
ZAP-70 phosphopeptide. The bound peptide is shown in white. Red
spheres represent ordered water molecules that bridge Cbl-N and
the bound peptide. Thin blue lines represent hydrogen bonds. In
the phosphotyrosine pocket, Tyr 274 in Cbl makes an 'edge-face'
interaction with the phosphotyrosine ring, and its hydroxyl
group hydrogen-bonds to the carbonyl oxygen of Gly 291 in the
ZAP-70 peptide. An arginine residue found in this position in
most SH2 domains makes an 'amino–aromatic' interaction with
the phosphotyrosine ring and also hydrogen-bonds with the
carbonyl of the pY-1 residue of the bound peptide^8. C-terminal
to the phosphotyrosine, the proline at position pY+4 in the
ZAP-70 peptide binds in a hydrophobic cleft formed by Tyr 307,
Phe 336 and Tyr 337, and the glutamic acid residue at pY+3
hydrogen-bonds with the backbone amide of His 320. c,
Superposition of the liganded (yellow) and unliganded (blue)
Cbl-N structures reveals a shift in the position of the SH2
domain upon phosphopeptide binding. The conformation of the 4H
and EF-hand domains is essentially identical in the two
structures. In the absence of phosphopeptide, the SH2 domain
makes little contact with the 4H domain and its position is
likely to vary, as we observe slightly different conformations
among the three molecules in the asymmetric unit. Phosphopeptide
binding induces a domain 'closure', in which the SH2 domain
rotates to pack against the helical domain, completing the
phosphotyrosine-binding pocket, as in d. d, Molecular surface
representation of the Cbl-N domain, coloured by domain. The 4H
domain (yellow) forms a portion of the phosphotyrosine-binding
pocket. Residues 289–297 of the bound ZAP-70 phosphopeptide
are shown as a stick model. The three N-terminal residues in the
peptide are disordered and are not included. In the liganded
structure, about 1, 200 Å^2 of the SH2 domain is buried as
a result of interaction with the other two domains; 500
Å^2 is buried in the interface with the 4H domain, and 700
Å^2 is buried in the interface with the EF hand. The 4H
and EF-hand domains share a solvent-excluding interface of 800
Å^2.
The above figure is reprinted
by permission from Macmillan Publishers Ltd:
Nature
(1999,
398,
84-90)
copyright 1999.
-carbon
trace of the complex. The bound ZAP-70 phosphopeptide is shown
in magenta. b, Stereo diagram showing the interactions with the
ZAP-70 phosphopeptide. The bound peptide is shown in white. Red
spheres represent ordered water molecules that bridge Cbl-N and
the bound peptide. Thin blue lines represent hydrogen bonds. In
the phosphotyrosine pocket, Tyr 274 in Cbl makes an 'edge-face'
interaction with the phosphotyrosine ring, and its hydroxyl
group hydrogen-bonds to the carbonyl oxygen of Gly 291 in the
ZAP-70 peptide. An arginine residue found in this position in
most SH2 domains makes an 'amino–aromatic' interaction with
the phosphotyrosine ring and also hydrogen-bonds with the
carbonyl of the pY-1 residue of the bound peptide^8. C-terminal
to the phosphotyrosine, the proline at position pY+4 in the
ZAP-70 peptide binds in a hydrophobic cleft formed by Tyr 307,
Phe 336 and Tyr 337, and the glutamic acid residue at pY+3
hydrogen-bonds with the backbone amide of His 320. c,
Superposition of the liganded (yellow) and unliganded (blue)
Cbl-N structures reveals a shift in the position of the SH2
domain upon phosphopeptide binding. The conformation of the 4H
and EF-hand domains is essentially identical in the two
structures. In the absence of phosphopeptide, the SH2 domain
makes little contact with the 4H domain and its position is
likely to vary, as we observe slightly different conformations
among the three molecules in the asymmetric unit. Phosphopeptide
binding induces a domain 'closure', in which the SH2 domain
rotates to pack against the helical domain, completing the
phosphotyrosine-binding pocket, as in d. d, Molecular surface
representation of the Cbl-N domain, coloured by domain. The 4H
domain (yellow) forms a portion of the phosphotyrosine-binding
pocket. Residues 289–297 of the bound ZAP-70 phosphopeptide
are shown as a stick model. The three N-terminal residues in the
peptide are disordered and are not included. In the liganded
structure, about 1, 200 Å^2 of the SH2 domain is buried as
a result of interaction with the other two domains; 500
Å^2 is buried in the interface with the 4H domain, and 700
Å^2 is buried in the interface with the EF hand. The 4H
and EF-hand domains share a solvent-excluding interface of 
800
Å^2.