1Q1E

The ATPase component of E. coli maltose transporter (MalK) in the nucleotide-free form

Summary for 1Q1E

• Entry DOI: 10.2210/pdb1q1e/pdb
• Related: 1Q12 1Q1B
• Descriptor: Maltose/maltodextrin transport ATP-binding protein malK (1 entity in total)
• Functional Keywords: atp-binding cassette, nucleotide-free form, sugar transport, transport protein
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane; Peripheral membrane protein: P68187
• Total number of polymer chains: 2
• Total formula weight: 84369.07

Authors

Chen, J.,Lu, G.,Lin, J.,Davidson, A.L.,Quiocho, F.A. (deposition date: 2003-07-19, release date: 2003-09-30, Last modification date: 2024-02-14)

Primary citation

Chen, J.,Lu, G.,Lin, J.,Davidson, A.L.,Quiocho, F.A.
A tweezers-like motion of the ATP-binding cassette dimer in an ABC transport cycle
Mol.Cell, 12:651-661, 2003

PubMed Abstract: The ATPase components of ATP binding cassette (ABC) transporters power the transporters by binding and hydrolyzing ATP. Major conformational changes of an ATPase are revealed by crystal structures of MalK, the ATPase subunit of the maltose transporter from Escherichia coli, in three different dimeric configurations. While other nucleotide binding domains or subunits display low affinity for each other in the absence of the transmembrane segments, the MalK dimer is stabilized through interactions of the additional C-terminal domains. In the two nucleotide-free structures, the N-terminal nucleotide binding domains are separated to differing degrees, and the dimer is maintained through contacts of the C-terminal regulatory domains. In the ATP-bound form, the nucleotide binding domains make contact and two ATPs lie buried along the dimer interface. The two nucleotide binding domains of the dimer open and close like a pair of tweezers, suggesting a regulatory mechanism for ATPase activity that may be tightly coupled to translocation.

PubMed: 14527411
DOI: 10.1016/j.molcel.2003.08.004

Experimental method

X-RAY DIFFRACTION (2.9 Å)