The dimerization motif of the glycophorin A transmembrane segment in membranes: importance of glycine residues.
The glycophorin A transmembrane segment homo-dimerizes to a right-handed pair of alpha-helices. Here, we identified the amino acid motif mediating this interaction within a natural membrane environment. Critical residues were grafted onto two different hydrophobic host sequences in a stepwise manner and self-assembly of the hybrid sequences was determined with the ToxR transcription activator system. Our results show that the motif LIxxGxxxGxxxT elicits a level of self-association equivalent to that of the original glycophorin A transmembrane segment. This motif is very similar to the one previously established in detergent solution. Interestingly, the central GxxxG motif by itself already induced strong self-assembly of host sequences and the three-residue spacing between both glycines proved to be optimal for the interaction. The GxxxG element thus appears to be the most crucial part of the interaction motif.
Brosig
B
B
Universität Heidelberg, Neurobiologie Department, Germany.
Langosch
D
D
D001426:Bacterial Proteins; D002455:Cell Division / Q000235:genetics; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D019281:Dimerization; D005998:Glycine / Q000737:chemistry; D006021:Glycophorins / Q000737:chemistry*; D008320:Maltose / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry; D011401:Promoter Regions, Genetic / Q000235:genetics; D011487:Protein Conformation; D015202:Protein Engineering / Q000379:methods; D017433:Protein Structure, Secondary; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D014157:Transcription Factors / Q000378:metabolism; D015533:Transcriptional Activation / Q000235:genetics
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D006021:Glycophorins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C066719:toxR protein, bacteria; D008320:Maltose; D005998:Glycine