Selectivity and conductance among the glycerol and water conducting aquaporin family of channels.
The atomic structures of a transmembrane water plus glycerol conducting channel (GlpF), and now of aquaporin Z (AqpZ) from the same species, Escherichia coli, bring the total to three atomic resolution structures in the aquaporin (AQP) family. Members of the AQP family each assemble as tetramers of four channels. Common helical axes support a wider channel in the glycerol plus water channel paradigm, GlpF. Water molecules form a single hydrogen bonded file throughout the 28 A long channel in AqpZ. The basis for absolute exclusion of proton or hydronium ion conductance through the line of water is explored using simulations.
Stroud
Robert M
RM
Department of Biochemistry and Biophysics, University of California, San Francisco, CA 94143-2240, USA. stroud@msg.ucsf.edu
Savage
David
D
Miercke
Larry J W
LJ
Lee
John K
JK
Khademi
Shahram
S
Harries
William
W
D000595:Amino Acid Sequence; D051398:Aquaporin 1; D020346:Aquaporins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D050260:Carbohydrate Metabolism; D004553:Electric Conductivity; D004563:Electrochemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020440:Gene Duplication; D005990:Glycerol / Q000378:metabolism; D008565:Membrane Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000737:chemistry; D011487:Protein Conformation; D017386:Sequence Homology, Amino Acid; D014867:Water / Q000378:metabolism
D020346:Aquaporins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D015221:Potassium Channels; C106425:aqpZ protein, E coli; D014867:Water; C078043:GlpF protein, E coli; D051398:Aquaporin 1; D005990:Glycerol