An investigation into the membrane-interactive potential of the Escherichia coli KpsE C-terminus.
Membrane binding via C-terminal amphiphilic alpha-helical structure is a novel anchoring mechanism, which has been characterised in a number of prokaryotic carboxypeptidases. Here, we have used graphical and DWIH analyses to ascertain if a similar anchoring mechanism may be utilised by the Escherichia coli KpsE protein in its binding to the periplasmic face of the inner membrane. The results of these analyses have been compared to those obtained for similar analyses of the C-terminal sequences of E. coli penicillin-binding proteins (PBPs) PBP5 and PBP6 which, are known to function as amphiphilic alpha-helical membrane anchors, and of melittin, a known membrane-interactive toxin. We have also used FTIR spectroscopy and lipid phase transition temperature analysis to investigate the interaction of a peptide homologue of KpsE C-terminal region with membrane lipid. Our results suggest that the KpsE C-terminal sequence has the potential to form an amphiphilic alpha-helix and that this alpha-helix could feature in the membrane binding of the protein.
Phoenix
D A
DA
Centre for Forensic Science, University of Central Lancashire, Preston, PR1 2HE, United Kingdom. daphoenix@uclan.ac.uk
Brandenburg
K
K
Harris
F
F
Seydel
U
U
Hammerton
T
T
Roberts
I S
IS
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D008560:Membrane Fluidity; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D026901:Membrane Transport Proteins; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C084729:kpsE protein, E coli