title: Genetic engineering of the phosphocarrier protein NPr of the Escherichia coli phosphotransferase system selectively improves sugar uptake activity.
abstract: The Escherichia coli phosphoenolpyruvate:sugar phosphotransferase system (PTS) in prokaryotes mediates the uptake and phosphorylation of its numerous substrates through a phosphoryl transfer chain where a phosphoryl transfer protein, HPr, transfers its phosphoryl group to any of several sugar-specific Enzyme IIA proteins in preparation for sugar transport. A phosphoryl transfer protein of the PTS, NPr, homologous to HPr, functions to regulate nitrogen metabolism and shows virtually no enzymatic cross-reactivity with HPr. Here we describe the genetic engineering of a "chimeric" HPr/NPr protein, termed CPr14 because 14 amino acid residues of the interface were replaced. CPr14 shows decreased activity with most PTS permeases relative to HPr, but increases activity with the broad specificity mannose permease. The results lead to the proposal that HPr is not optimal for most PTS permeases but instead represents a compromise with suboptimal activity for most PTS permeases. The evolutionary implications are discussed.
authors: Departamento de Ingeniería Celular y Biocatálisis del Instituto de Biotecnología, Universidad Nacional Autónoma de México, Avenue Universidad 2001, Cuernavaca, Morelos, México, P. C. 62210.
authors: Yossef
authors: Y
authors: Lopez-de Los Santos
authors: Henry
authors: H
authors: Chan
authors: Vito A
authors: VA
authors: Cantu
authors: Rachael
authors: R
authors: Rettner
authors: Filiberto
authors: F
authors: Sanchez
authors: Zhongge
authors: Z
authors: Zhang
authors: Milton H
authors: MH
authors: Saier
authors: Xavier
authors: X
authors: Soberon
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D005818:Genetic Engineering; D028044:Phosphate-Binding Proteins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; C502371:NPr protein, E coli; D028044:Phosphate-Binding Proteins; D011993:Recombinant Fusion Proteins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C030182:phosphocarrier protein HPr; C037992:phosphoenolpyruvate-mannose phosphotransferase