title: A study on the C-terminal membrane anchoring of Escherichia coli penicillin-binding protein 5.
abstract: Escherichia coli penicillin-binding protein 5 (PBP5) anchors to the inner membrane in a pH-dependent manner via a C-terminal amphiphilic alpha-helix. Low pH was found to enhance both levels of PBP5 membrane anchoring and levels of alpha-helicity in an aqueous PBP5 C-terminal homologue, which led to the suggestion that levels of PBP5 membrane anchoring are related to levels of PBP5 C-terminal alpha-helicity. Here we have used Fourier-transformed infrared spectroscopy (FTIR) and a peptide homologue of the PBP5 C-terminal sequence to investigate the effect of pH on the conformational behavior of this sequence at a lipid interface and on its ability to interact with lipid. Our results suggest that the membrane-anchoring mechanism of PBP5 is unlikely to involve conformational change in the protein's C-terminal region and may therefore involve conformational changes in the protein's ectomembranous domain.
authors.affiliation: Division of Biophysics, Forschunginstitute Borstel, D-2061 Borstel, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Brandenburg
authors.forename: F
authors.initials: F
authors.lastname: Harris
authors.forename: D A
authors.initials: DA
authors.lastname: Phoenix
authors.forename: U
authors.initials: U
authors.lastname: Seydel
mesh_terms: D001426:Bacterial Proteins; D002352:Carrier Proteins / Q000737:chemistry*; D002462:Cell Membrane / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D006602:Hexosyltransferases; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry*; D046915:Penicillin-Binding Proteins; D010455:Peptides / Q000737:chemistry; D010458:Peptidyl Transferases; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D008055:Lipids; D046915:Penicillin-Binding Proteins; D010455:Peptides; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase