Part:BBa_K190028

GlpF

[http://2009.igem.org/Team:Groningen/Project/Transport#GlpF GlpF] is an aquaglyceroporin channel that facilitates the transport of As(III). GlpF is an aquaglycerol porin of E.coli which facilitates not only glycerol import, but also arsenic (As) and antimone (Sb) import (Fu, DX, et al.2000, Meng, YL, et al.2004, Porquet, A, et al.2007, Rosen, BR, et al.2009). It has homologues in other organisms; Fps1p has shown to facilitate arsenic import in yeast and AQP9 is the mammalian homologue (Porquet, A, et al.2007, Rosen, BR, et al.2009). The GlpF aquaglycerol porin is a membrane protein with a symmetric arrangement of four independent GlpF channels. One monomer of this tetramer GlpF porin consists of six transmembrane and two half membrane-spanning α-helices that form a right-handed helical bundle around the channel. The channel has a diameter of ~15Å at the periplasmid end, which constricts towards a diameter of ~3.8Å at the beginning of a 28 Å long selective channel that ends at the cytoplasmic end (Fu, DX, et al.2000). The GlpF is a stereospecific channel that is thought to be more selective on molecular size than on chemical structure (Fu, DX, et al.2000, Heller, KB, et al.1980). It does allow transport of a variance of polyhydric alcohols, glycerol being one of them, and arsenic and antimone (Fu, DX, et al.2000, Meng, YL, et al.2004, Porquet, A, et al.2007,Rosen, BR, et al.2009, Heller, KB, et al.1980). Carbon sugars and ions are shown to be unable to be transported by GlpF (Heller, KB, et al.1980). At physiological pH arsenic and antimone are not present in their ionic state but rather as As(OH)3 and Sb(OH)3 (Rosen, BR, et al.2009). These elements show a charge distribution similar to glycerol and a smaller but comparable volume. The structural similarities are thought to be the reason for the possibility of these elements to be transported in the cell by GlpF (Porquet, A, et al.2007). If GlpF behaves as a nonsaturable transporter, a transport rate of 1umol of glycerol is transported per minute per mgr of cell protein (Heller, KB, et al.1980). The transport rate of GlpF for arsenic is estimated to be..

references:

• [http://2009.igem.org/Team:Groningen/Literature#Meng2004 Meng 2004]
• [http://2009.igem.org/Team:Groningen/Literature#Rosen2009 Rosen 2009]
• [http://2009.igem.org/Team:Groningen/Literature#Porquet,A,etal2007 Porquet, A, et al.2007]
• [http://2009.igem.orgTeam:Groningen/Literature#Fu,DX,etal2000 Fu, DX, et al.2000]
• [http://2009.igem.orgTeam:Groningen/Literature#Heller,KB,etal1980 Heller, KB, et al.1980]

Sequence and Features

Assembly Compatibility:

• 10
  COMPATIBLE WITH RFC[10]
• 12
  COMPATIBLE WITH RFC[12]
• 21
  COMPATIBLE WITH RFC[21]
• 23
  COMPATIBLE WITH RFC[23]
• 25
  INCOMPATIBLE WITH RFC[25]

  Illegal NgoMIV site found at 283
  
• 1000
  COMPATIBLE WITH RFC[1000]