title: Analysis of the membrane-anchoring properties of the putative amphiphilic alpha-helical anchor at the C-terminus of Escherichia coli PBP 6.
abstract: Penicillin-binding protein (PBP) 6 is anchored to the periplasmic face of the Escherichia coli inner membrane. Analysis of the C-terminal 20 amino acids of PBP 6 implies the presence of a C-terminal amphiphilic alpha-helical anchor comparable to that of PBP 5. A C-terminal deletion of PBP 6 was constructed; it resulted in the release of the protein from the inner membrane into the periplasm, thus confirming that this region is essential for anchoring. Treatment of E. coli K12 membrane vesicles with various reagents was used to probe the membrane-binding characteristics of both PBP 5 and PBP 6. The results indicate that, although the strength of membrane anchoring of PBP 6 is weaker than that of PBP 5, both modes of anchoring involve a large hydrophobic element and have similar membrane-binding characteristics. This is in agreement with the hypothesis that both proteins exhibit the same novel method of anchoring.
authors.affiliation: Department of Applied Biology, University of Central Lancashire, Preston, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Phoenix
authors.forename: S E
authors.initials: SE
authors.lastname: Peters
authors.forename: M A
authors.initials: MA
authors.lastname: Ramzan
authors.forename: J M
authors.initials: JM
authors.lastname: Pratt
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005798:Genes, Bacterial; D006602:Hexosyltransferases; D008969:Molecular Sequence Data; D002267:Muramoylpentapeptide Carboxypeptidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D046915:Penicillin-Binding Proteins; D010406:Penicillins / Q000378:metabolism*; D010458:Peptidyl Transferases; D017433:Protein Structure, Secondary; D017384:Sequence Deletion
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D046915:Penicillin-Binding Proteins; D010406:Penicillins; D010458:Peptidyl Transferases; D006602:Hexosyltransferases; D002267:Muramoylpentapeptide Carboxypeptidase