8WON

Cryo-EM structure of the 10-subunits Mmp1 complex from Mycobacterium smegmatis

Summary for 8WON

• Entry DOI: 10.2210/pdb8won/pdb
• EMDB information: 37693
• Descriptor: Major membrane protein I (1 entity in total)
• Functional Keywords: 10-subunits mmp1 complex, structural protein
• Biological source: Mycolicibacterium smegmatis
• Total number of polymer chains: 10
• Total formula weight: 317698.03

Authors

Zhang, M.,Tang, Y.,Gao, Y.,Liu, X.,Lan, W.,Liu, Y.,Ma, M. (deposition date: 2023-10-07, release date: 2025-01-01, Last modification date: 2025-06-18)

Primary citation

Tang, Y.,Liu, Y.,Zhang, M.,Lan, W.,Ma, M.,Chen, C.,Wu, S.,Chen, R.,Yan, Y.,Feng, L.,Li, Y.,Guddat, L.W.,Gao, Y.,Liu, X.,Rao, Z.
The structural and functional analysis of mycobacteria cysteine desulfurase-loaded encapsulin.
Commun Biol, 7:1656-1656, 2024

PubMed Abstract: Encapsulin nanocompartments loaded with dedicated cargo proteins via unique targeting peptides, play a key role in stress resistance, iron storage and natural product biosynthesis. Mmp1 and cysteine desulfurase (Enc-CD) have been identified as the most abundant representatives of family 2 encapsulin systems. However, the molecular assembly, catalytic mechanism, and physiological functions of the Mmp1 encapsulin system have not been studied in detail. Here we isolate and characterize an Enc-CD-loaded Mmp1 encapsulin system from Mycobacterium smegmatis mc155. The cryo-EM structure of the Mmp1 encapsulin and the crystal structure of the naked cargo Enc-CD have been determined. The structure shows that the Mmp1 protomer assembles two conformation models, the icosahedron (T = 1) and homodecamer, with the resolution of 2.60 Å and 2.69 Å. The Enc-CD at 2.10 Å resolution is dimeric and loaded into the Mmp1 (T = 1) encapsulin through the N-terminal long disordered region. Mmp1 encapsulin protects Enc-CD against oxidation as well as to maintain structural stability. These studies provide new insights into the mechanism by which Enc-CD-loaded encapsulin stores sulfur and provides a framework for discovery of new anti-mycobacterial therapeutics.

PubMed: 39702509
DOI: 10.1038/s42003-024-07299-8

Experimental method

ELECTRON MICROSCOPY (2.69 Å)