3ZNG

Ankyrin repeat and SOCS-box protein 9 (ASB9) in complex with ElonginB and ElonginC

Summary for 3ZNG

• Entry DOI: 10.2210/pdb3zng/pdb
• Descriptor: ANKYRIN REPEAT AND SOCS BOX PROTEIN 9, TRANSCRIPTION ELONGATION FACTOR B POLYPEPTIDE 1, TRANSCRIPTION ELONGATION FACTOR B POLYPEPTIDE 2, ... (5 entities in total)
• Functional Keywords: transcription, cullin-ring ligase
• Biological source: HOMO SAPIENS (HUMAN); More
• Cellular location: Mitochondrion: Q96DX5; Nucleus (Probable): Q15369 Q15370
• Total number of polymer chains: 6
• Total formula weight: 107158.32

Authors

Thomas, J.,Van Molle, I.,Ciulli, A. (deposition date: 2013-02-14, release date: 2013-12-04, Last modification date: 2023-12-20)

Primary citation

Thomas, J.C.,Matak-Vinkovic, D.,Van Molle, I.,Ciulli, A.
Multimeric Complexes Among Ankyrin-Repeat and Socs-Box Protein 9 (Asb9), Elonginbc, and Cullin 5: Insights Into the Structure and Assembly of Ecs-Type Cullin-Ring E3 Ubiquitin Ligases.
Biochemistry, 52:5236-, 2013

PubMed Abstract: Proteins of the ankyrin-repeat and SOCS-box (ASB) family act as the substrate-recognition subunits of ECS-type (ElonginBC-Cullin-SOCS-box) Cullin RING E3 ubiquitin ligase (CRL) complexes that catalyze the specific polyubiquitination of cellular proteins to target them for degradation by the proteasome. Therefore, ASB multimeric complexes are involved in numerous cell processes and pathways; however, their interactions, assembly, and biological roles remain poorly understood. To enhance our understanding of ASB CRL systems, we investigated the structure, affinity, and assembly of the quaternary multisubunit complex formed by ASB9, Elongin B, Elongin C (EloBC), and Cullin 5. Here, we describe the application of several biophysical techniques including differential scanning fluorimetry, isothermal titration calorimetry (ITC), nanoelectrospray ionization, and ion-mobility mass spectrometry (IM-MS) to provide structural and thermodynamic information for a quaternary ASB CRL complex. We find that ASB9 is unstable alone but forms a stable ternary complex with EloBC that binds with high affinity to the Cullin 5 N-terminal domain (Cul5NTD) but not to Cul2NTD. The structure of the monomeric ASB9-EloBC-Cul5NTD quaternary complex is revealed by molecular modeling and is consistent with IM-MS and temperature-dependent ITC data. This is the first experimental study to validate structural information for the assembly of the quaternary N-terminal region of an ASB CRL complex. The results suggest that ASB E3 ligase complexes function and assemble in an analogous manner to that of other CRL systems and provide a platform for further molecular investigation of this important protein family. The data reported here will also be of use for the future development of chemical probes to examine the biological function and modulation of other ECS-type CRL systems.

PubMed: 23837592
DOI: 10.1021/BI400758H

Experimental method

X-RAY DIFFRACTION (2.85 Å)