title: Glycine-144 is required for efficient folding of outer membrane protein PhoE of Escherichia coli K12.
abstract: Short stretches of similar sequences have been detected in unrelated bacterial outer membrane proteins (Nikaido and Wu (1984) Proc. Natl. Acad. Sci. USA 81, 1048-1052). In the most pronounced similarity region, only a glycine residue is absolutely conserved. To investigate whether this glycine residue is essential for outer membrane incorporation, oligonucleotide-directed mutagenesis was applied to replace this residue, i.e. Gly-144, as well as two other Gly-residues in pore protein PhoE. Substitution of Gly-52 and Gly-258 by Ala and Val, respectively, did not influence outer membrane incorporation. However, the substitution of Gly-144 by Leu affected the efficiency of outer membrane incorporation. After in vitro synthesis this mutant protein was less efficiently precipitated with monoclonal antibodies that recognize conformational epitopes than wild-type PhoE, showing that the mutation interferes with correct folding of the protein.
authors.affiliation: Department of Molecular Cell Biology, State University of Utrecht, The Netherlands.
authors.forename: H
authors.initials: H
authors.lastname: de Cock
authors.forename: N
authors.initials: N
authors.lastname: Quaedvlieg
authors.forename: D
authors.initials: D
authors.lastname: Bosch
authors.forename: M
authors.initials: M
authors.lastname: Scholten
authors.forename: J
authors.initials: J
authors.lastname: Tommassen
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D004252:DNA Mutational Analysis; D004926:Escherichia coli; D005998:Glycine / Q000737:chemistry; D046911:Macromolecular Substances; D018272:Porins; D011233:Precipitin Tests; D011994:Recombinant Proteins / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D001425:Bacterial Outer Membrane Proteins; D046911:Macromolecular Substances; D018272:Porins; D011994:Recombinant Proteins; D005998:Glycine