Structure determination of the small ubiquitin-related modifier SUMO-1
The recently discovered small ubiquitin-related modifier SUMO-1 belongs to the growing family of ubiquitin-related proteins involved in postranslational protein modification. Unlike ubiquitin, SUMO-1 does not appear to target proteins for degradation but seems to be involved in the modulation of pro...
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| Main Authors: | , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
10 July 1998
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| In: |
Journal of molecular biology
Year: 1998, Volume: 280, Issue: 2, Pages: 275-286 |
| ISSN: | 1089-8638 |
| DOI: | 10.1006/jmbi.1998.1839 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1006/jmbi.1998.1839 Verlag, lizenzpflichtig, Volltext: https://www.sciencedirect.com/science/article/pii/S0022283698918393 
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| Author Notes: | Peter Bayer, Andreas Arndt, Susanne Metzger, Rohit Mahajan, Frauke Melchior, Rainer Jaenicke, Jörg Becker |
| Summary: | The recently discovered small ubiquitin-related modifier SUMO-1 belongs to the growing family of ubiquitin-related proteins involved in postranslational protein modification. Unlike ubiquitin, SUMO-1 does not appear to target proteins for degradation but seems to be involved in the modulation of protein-protein interactions. Independent studies demonstrate an essential function of SUMO-1 in the regulation of nucleo-cytoplasmic transport, and suggest a role in cell-cycle regulation and apoptosis. Here, we present the first three-dimensional structure of SUMO-1 solved by NMR. Although having only 18% amino acid sequence identity with ubiquitin, the overall structure closely resembles that of ubiquitin, featuring the ββαββαβ fold of the ubiquitin protein family. In addition, the position of the two C-terminal Gly residues required for isopeptide bond formation is conserved between ubiquitin and SUMO-1. The most prominent feature of SUMO-1 is a long and highly flexible N terminus, which protrudes from the core of the protein and which is absent in ubiquitin. Furthermore, ubiquitin Lys48, required to generate ubiquitin polymers, is substituted in SUMO-1 by Gln69 at the same position, which provides an explanation of why SUMO-1 has not been observed to form polymers. Moreover, the hydrophobic core of SUMO-1 and ubiquitin is maintained by conserved hydrophobic residues, whereas the overall charge topology of SUMO-1 and ubiquitin differs significantly, suggesting specific modifying enzymes and target proteins for both proteins. |
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| Item Description: | Online verfügbar: 25. Mai 2022 Gesehen am 05.09.2023 |
| Physical Description: | Online Resource |
| ISSN: | 1089-8638 |
| DOI: | 10.1006/jmbi.1998.1839 |