5KWA

complete structure of the Mycobacterium tuberculosis proteasomal ATPase Mpa

Summary for 5KWA

• Entry DOI: 10.2210/pdb5kwa/pdb
• Descriptor: Proteasome-associated ATPase, ADENOSINE-5'-DIPHOSPHATE, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: proteasomal atpase, hydrolase
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 2
• Total formula weight: 110869.11

Authors

Wang, T.,WU, Y.J. (deposition date: 2016-07-17, release date: 2017-06-07, Last modification date: 2023-11-08)

Primary citation

Wu, Y.,Hu, K.,Li, D.,Bai, L.,Yang, S.,Jastrab, J.B.,Xiao, S.,Hu, Y.,Zhang, S.,Darwin, K.H.,Wang, T.,Li, H.
Mycobacterium tuberculosis proteasomal ATPase Mpa has a beta-grasp domain that hinders docking with the proteasome core protease
Mol. Microbiol., 105:227-241, 2017

PubMed Abstract: Mycobacterium tuberculosis (Mtb) has a proteasome system that is essential for its ability to cause lethal infections in mice. A key component of the system is the proteasomal adenosine triphosphatase (ATPase) Mpa, which captures, unfolds, and translocates protein substrates into the Mtb proteasome core particle for degradation. Here, we report the crystal structures of near full-length hexameric Mtb Mpa in apo and ADP-bound forms. Surprisingly, the structures revealed a ubiquitin-like β-grasp domain that precedes the proteasome-activating carboxyl terminus. This domain, which was only found in bacterial proteasomal ATPases, buries the carboxyl terminus of each protomer in the central channel of the hexamer and hinders the interaction of Mpa with the proteasome core protease. Thus, our work reveals the structure of a bacterial proteasomal ATPase in the hexameric form, and the structure finally explains why Mpa is unable to stimulate robust protein degradation in vitro in the absence of other, yet-to-be-identified co-factors.

PubMed: 28419599
DOI: 10.1111/mmi.13695

Experimental method

X-RAY DIFFRACTION (2.9 Å)