3FH6

Crystal structure of the resting state maltose transporter from E. coli

Summary for 3FH6

• Entry DOI: 10.2210/pdb3fh6/pdb
• Related: 1Q1B 1Q1E 2R6G
• Descriptor: Maltose transport system permease protein malF, Maltose transport system permease protein malG, Maltose/maltodextrin import ATP-binding protein malK (3 entities in total)
• Functional Keywords: maltose transporter, ground state, abc transporter, membrane protein, cell inner membrane, cell membrane, membrane, sugar transport, transmembrane, transport, atp-binding, hydrolase, nucleotide-binding, transport protein
• Biological source: Escherichia coli; More
• Cellular location: Cell inner membrane ; Multi-pass membrane protein ; Periplasmic side : P02916; Cell inner membrane ; Multi- pass membrane protein : P68183; Cell inner membrane ; Peripheral membrane protein : P68187
• Total number of polymer chains: 8
• Total formula weight: 339416.82

Authors

Khare, D.,Oldham, M.L.,Orelle, C.,Davidson, A.L.,Chen, J. (deposition date: 2008-12-08, release date: 2009-03-03, Last modification date: 2023-09-06)

Primary citation

Khare, D.,Oldham, M.L.,Orelle, C.,Davidson, A.L.,Chen, J.
Alternating access in maltose transporter mediated by rigid-body rotations.
Mol.Cell, 33:528-536, 2009

PubMed Abstract: ATP-binding cassette transporters couple ATP hydrolysis to substrate translocation through an alternating access mechanism, but the nature of the conformational changes in a transport cycle remains elusive. Previously we reported the structure of the maltose transporter MalFGK(2) in an outward-facing conformation in which the transmembrane (TM) helices outline a substrate-binding pocket open toward the periplasmic surface and ATP is poised for hydrolysis along the closed nucleotide-binding dimer interface. Here we report the structure of the nucleotide-free maltose transporter in which the substrate binding pocket is only accessible from the cytoplasm and the nucleotide-binding interface is open. Comparison of the same transporter crystallized in two different conformations reveals that alternating access involves rigid-body rotations of the TM subdomains that are coupled to the closure and opening of the nucleotide-binding domain interface. The comparison also reveals that point mutations enabling binding protein-independent transport line dynamic interfaces in the TM region.

PubMed: 19250913
DOI: 10.1016/j.molcel.2009.01.035

Experimental method

X-RAY DIFFRACTION (4.5 Å)