Smt3 belongs to a growing family of ubiquitin-related proteins involved in
posttranslational protein modification. Independent studies demonstrate an
essential function of Smt3 in the regulation of nucleocytoplasmic transport, and
suggest a role in cell-cycle regulation. Here we report the high-resolution NMR
structure of yeast Smt3 in the complex free form. Our comparison of the Smt3 NMR
structure with the Smt3 crystal structure in complex with the C-Terminal Ulp1
protease domain revealed large structural differences in the binding surface,
which is also involved in the Smt3-Ubc-9 interaction detected by NMR. The
structural differences in the region indicate the important functions of
conserved residues in less structurally defined sequences.
Figure 5.
Fig. 5. NMR structure of Smt3. (A) Stereo superposition of
20 selected conformers with the lowest target functions from the
final DYANA calculations. (B) A ribbon diagram showing the
NMR-derived tertiary structure used in this study. The average
structure was generated and analyzed by MolMol.
Figure 7.
Fig. 7. A stereo diagram of the backbone C^ atom
coordinates of NMR solution structure of Smt3 (current
structure, red) overlaid with (A) that of SUMO-1 structure
(blue) obtained from heteronuclear NMR. (B) That of the X-ray
crystal structure of Smt3 (green) in complex with the C-Terminal
Ulp1 protease domain.
The above figures are
reprinted
by permission from the Protein Society:
Protein Sci
(2002,
11,
1482-1491)
copyright 2002.
atom
coordinates of NMR solution structure of Smt3 (current
structure, red) overlaid with (A) that of SUMO-1 structure
(blue) obtained from heteronuclear NMR. (B) That of the X-ray
crystal structure of Smt3 (green) in complex with the C-Terminal
Ulp1 protease domain.
