KEY RESOURCES TABLE

REAGENT or RESOURCE	SOURCE	IDENTIFIER
Chemicals, peptides, and recombinant proteins
HEPES	Sigma-Aldrich	Cat# H4034
Ammonium sulfate	Sigma-Aldrich	Cat# A4418
Magnesium chloride	Sigma-Aldrich	Cat# M8266
Glycerol	Sigma-Aldrich	Cat# G5516
Triton X-100	Sigma-Aldrich	Cat# 93443
2-Mercaptoetanol	Sigma-Aldrich	Cat# M3148
Biotin	IBA Lifesciences	Cat# 2-1016-002
Trypsin	Thermo Fisher	Cat# 90058
cOmplete EDTA-free Protease Inhibitor Cocktail	Roche	Cat# 11873580001 (Sigma)
Critical commercial assays
Strep-tactin XT 4Flow FPLC column, 1 ml	IBA Lifesciences	Cat# 2-5023-001
Amicon Ultra Centrifugal Filter, 10 kDa MWCO	Sigma-Aldrich	Cat# UFC5010
C-flat 1.2/1.3, 300 mesh	Protochips	Cat# CF-1.2/1.3-3CU-50
Deposited data
X-ray crystal structure of PaMCC	Huang et al.22	PDB: 3U9S
CryoEM structure of LtMCC	Hu et al.23	PDB: 8F3D
X-ray crystal structure of E coli BC	Thoden et al.30	PDB: 1DV1
X-ray crystal structure of E coli BC (ATP-bound)	Thoden et al.30	PDB: 1DV2
CryoEM structure of PC	Lopez-Alonso et al.32	PDB: 7ZZ3
X-ray crystal structure of E coli BCCP	Athappilly & Hendrickson27	PDB: 1BDO
CryoEM structure of TbMCC	This paper	PDB: 8RTH
CryoEM map of TbMCC	This paper	EMDB: EMD-19492
Experimental models: Cell lines
Trypanosoma brucei strain Lister 427	ATCC	Cat# PRA-380
Software and algorithms
Relion	Zivanov et al.35	https://relion.readthedocs.io/en/release-3.1/
MotionCor2	Zheng et al.36	https://emcore.ucsf.edu/ucsf-software
CryoSPARC	Punjani et al.37	https://cryosparc.com
UCSF Chimera	Pettersen et al.38	https://www.rbvi.ucsf.edu/chimera/
ChimeraX	Meng et al.39	https://www.cgl.ucsf.edu/chimerax/
Coot	Emsley et al.40	https://www2.mrc-lmb.cam.ac.uk/personal/pemsley/coot/
Clustal Omega	Sievers & Higgins41	http://www.ebi.ac.uk/Tools/msa/clustalo
Phenix	Liebschner et al.42	https://phenix-online.org/documentation/index.html
AlphaFold	Jumper et al.43	https://github.com/sokrypton/ColabFold
ESPript3	Gouet et al.44	https://espript.ibcp.fr/ESPript/ESPript/
CASTp	Tian et al.45	http://sts.bioe.uic.edu/
PDBePISA	Krissinel and Henrick46	https://www.ebi.ac.uk/pdbe/pisa/
Pymol	Schrödinger	https://pymol.org/2/