2V8N

Wild-type Structure of Lactose Permease

Summary for 2V8N

• Entry DOI: 10.2210/pdb2v8n/pdb
• Related: 1M2U 1PV6 1PV7 2CFP 2CFQ
• Descriptor: LACTOSE PERMEASE (1 entity in total)
• Functional Keywords: transmembrane, inner membrane, sugar transport, symport, membrane, transport, formylation, transport protein
• Biological source: ESCHERICHIA COLI
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P02920
• Total number of polymer chains: 2
• Total formula weight: 93061.78

Authors

Guan, L.,Mirza, O.,Verner, G.,Iwata, S.,Kaback, H.R. (deposition date: 2007-08-09, release date: 2007-09-11, Last modification date: 2023-12-13)

Primary citation

Guan, L.,Mirza, O.,Verner, G.,Iwata, S.,Kaback, H.R.
Structural Determination of Wild-Type Lactose Permease.
Proc.Natl.Acad.Sci.USA, 104:15294-, 2007

PubMed Abstract: Here we describe an x-ray structure of wild-type lactose permease (LacY) from Escherichia coli determined by manipulating phospholipid content during crystallization. The structure exhibits the same global fold as the previous x-ray structures of a mutant that binds sugar but cannot catalyze translocation across the membrane. LacY is organized into two six-helix bundles with twofold pseudosymmetry separated by a large interior hydrophilic cavity open only to the cytoplasmic side and containing the side chains important for sugar and H(+) binding. To initiate transport, binding of sugar and/or an H(+) electrochemical gradient increases the probability of opening on the periplasmic side. Because the inward-facing conformation represents the lowest free-energy state, the rate-limiting step for transport may be the conformational change leading to the outward-facing conformation.

PubMed: 17881559
DOI: 10.1073/PNAS.0707688104

Experimental method

X-RAY DIFFRACTION (3.6 Å)