7F7X

Protein complex between phosphorylated ubiquitin and Ubqln2 UBA

Summary for 7F7X

• Entry DOI: 10.2210/pdb7f7x/pdb
• NMR Information: BMRB: 36427
• Descriptor: Polyubiquitin-B, Ubiquilin-2 (2 entities in total)
• Functional Keywords: protein-protein interaction; phosphorylation; proteasomal shuttle factor; ubiquitin-associated domain; induced fit, protein binding
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 13528.28

Authors

Qin, L.Y.,Dong, X.,Tang, C. (deposition date: 2021-06-30, release date: 2022-05-18, Last modification date: 2024-11-13)

Primary citation

Qin, L.Y.,Gong, Z.,Liu, K.,Dong, X.,Tang, C.
Kinetic Constraints in the Specific Interaction between Phosphorylated Ubiquitin and Proteasomal Shuttle Factors.
Biomolecules, 11:-, 2021

PubMed Abstract: Ubiquitin (Ub) specifically interacts with the Ub-associating domain () in a proteasomal shuttle factor, while the latter is involved in either proteasomal targeting or self-assembly coacervation. PINK1 at S65 and makes Ub alternate between C-terminally relaxed () and retracted conformations (). Using NMR spectroscopy, we show that but not preferentially interacts with the from two proteasomal shuttle factors Ubqln2 and Rad23A. Yet discriminatorily, Ubqln2- binds to more tightly than Rad23A does and selectively enriches upon complex formation. Further, we determine the solution structure of the complex between Ubqln2- and and uncover the thermodynamic basis for the stronger interaction. NMR kinetics analysis at different timescales further suggests an indued-fit binding mechanism for interaction. Notably, at a relatively low saturation level, the dissociation rate of the complex is comparable with the exchange rate between and . Thus, a kinetic constraint would dictate the interaction between Ub and , thus fine-tuning the functional state of the proteasomal shuttle factors.

PubMed: 34356632
DOI: 10.3390/biom11071008

Experimental method

SOLUTION NMR