4MKI

Cobalt transporter ATP-binding subunit

Summary for 4MKI

• Entry DOI: 10.2210/pdb4mki/pdb
• Descriptor: Energy-coupling factor transporter ATP-binding protein EcfA2, SULFATE ION, DODECYL-BETA-D-MALTOSIDE, ... (4 entities in total)
• Functional Keywords: nucleotide-binding domain, ecf type cobalt transporter, hydrolase
• Biological source: Thermoanaerobacter tengcongensis
• Cellular location: Cell membrane; Peripheral membrane protein (By similarity): Q8R7Y5
• Total number of polymer chains: 2
• Total formula weight: 68703.72

Authors

Yu, Y.,Zhang, L.,Chai, C.L.,Heymann, D. (deposition date: 2013-09-05, release date: 2013-10-30, Last modification date: 2024-03-20)

Primary citation

Chai, C.L.,Yu, Y.,Zhuo, W.,Zhao, H.,Li, X.,Wang, N.,Chai, J.,Yang, M.
Structural basis for a homodimeric ATPase subunit of an ECF transporter
Protein Cell, 4:793-801, 2013

PubMed Abstract: The transition metal cobalt, an essential cofactor for many enzymes in prokaryotes, is taken up by several specific transport systems. The CbiMNQO protein complex belongs to type-1 energy-coupling factor (ECF) transporters and is a widespread group of microbial cobalt transporters. CbiO is the ATPase subunit (A-component) of the cobalt transporting system in the gram-negative thermophilic bacterium Thermoanaerobacter tengcongensis. Here we report the crystal structure of a nucleotide-free CbiO at a resolution of 2.3 Å. CbiO contains an N-terminal canonical nucleotide-binding domain (NBD) and C-terminal helical domain. Structural and biochemical data show that CbiO forms a homodimer mediated by the NBD and the C-terminal domain. Interactions mainly via conserved hydrophobic amino acids between the two C-terminal domains result in formation of a four-helix bundle. Structural comparison with other ECF transporters suggests that non-conserved residues outside the T-component binding groove in the A component likely act as a specificity determinant for T components. Together, our data provide information on understanding of the structural organization and interaction of the CbiMNQO system.

PubMed: 24104393
DOI: 10.1007/s13238-013-3915-y

Experimental method

X-RAY DIFFRACTION (2.3 Å)