1A5R

STRUCTURE DETERMINATION OF THE SMALL UBIQUITIN-RELATED MODIFIER SUMO-1, NMR, 10 STRUCTURES

Summary for 1A5R

• Entry DOI: 10.2210/pdb1a5r/pdb
• Descriptor: SUMO-1 (1 entity in total)
• Functional Keywords: sumo-1, post-translational protein modification, ubiquitin-like proteins, targeting protein
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus membrane: P63165
• Total number of polymer chains: 1
• Total formula weight: 11719.13

Authors

Bayer, P.,Arndt, A.,Metzger, S.,Mahajan, R.,Melchior, F.,Jaenicke, R.,Becker, J. (deposition date: 1998-02-18, release date: 1998-10-14, Last modification date: 2024-05-22)

Primary citation

Bayer, P.,Arndt, A.,Metzger, S.,Mahajan, R.,Melchior, F.,Jaenicke, R.,Becker, J.
Structure determination of the small ubiquitin-related modifier SUMO-1.
J.Mol.Biol., 280:275-286, 1998

PubMed Abstract: 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 betabetaalphabetabetaalphabeta 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.

PubMed: 9654451
DOI: 10.1006/jmbi.1998.1839

Experimental method

SOLUTION NMR