P-Aminobenzoate synthesis in Escherichia coli: Purification and characterization of PabB as aminodeoxychorismate synthase and enzyme X as aminodeoxychorismate lyase

Qizhuang Ye, Jun Liu, Christopher T. Walsh

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

The Escherichia coli pabA and pabB genes have been overexpressed separately and in tandem. Using purified PabB, we have confirmed the recent suggestion that PabB needs an additional protein, enzyme X, to convert chorismate and NH3 to p-aminobenzoate (PABA). With chorismate and NH3, pure PabB generates an intermediate presumed to be 4-amino-4-deoxychorismate based upon UV/visible spectroscopy and enzymatic and nonenzymatic transformations. The PabB-catalyzed interconversion of chorismate and isolated aminodeoxychorismate is readily reversible. With pure PabB as a stoichiometric assay reagent, enzyme X was purified ≈800-fold to near homogeneity as an apparent homodimer of 50 kDa from E. coli. Enzyme X shows no activity on chorismate but quantitatively converts the preformed aminodeoxychorismate into p-aminobenzoate and pyruvate, acting thereby as an aminodeoxychorismate lyase.

Original languageEnglish (US)
Pages (from-to)9391-9395
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume87
Issue number23
StatePublished - 1990
Externally publishedYes

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Aminobenzoates
para-Aminobenzoates
Escherichia coli
Enzyme Assays
Enzymes
Pyruvic Acid
Spectrum Analysis
Genes
Proteins
aminodeoxychorismate synthase
aminodeoxychorismate lyase

Keywords

  • Chorismate
  • Folate biosynthesis

ASJC Scopus subject areas

  • Genetics
  • General

Cite this

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title = "P-Aminobenzoate synthesis in Escherichia coli: Purification and characterization of PabB as aminodeoxychorismate synthase and enzyme X as aminodeoxychorismate lyase",
abstract = "The Escherichia coli pabA and pabB genes have been overexpressed separately and in tandem. Using purified PabB, we have confirmed the recent suggestion that PabB needs an additional protein, enzyme X, to convert chorismate and NH3 to p-aminobenzoate (PABA). With chorismate and NH3, pure PabB generates an intermediate presumed to be 4-amino-4-deoxychorismate based upon UV/visible spectroscopy and enzymatic and nonenzymatic transformations. The PabB-catalyzed interconversion of chorismate and isolated aminodeoxychorismate is readily reversible. With pure PabB as a stoichiometric assay reagent, enzyme X was purified ≈800-fold to near homogeneity as an apparent homodimer of 50 kDa from E. coli. Enzyme X shows no activity on chorismate but quantitatively converts the preformed aminodeoxychorismate into p-aminobenzoate and pyruvate, acting thereby as an aminodeoxychorismate lyase.",
keywords = "Chorismate, Folate biosynthesis",
author = "Qizhuang Ye and Jun Liu and Walsh, {Christopher T.}",
year = "1990",
language = "English (US)",
volume = "87",
pages = "9391--9395",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
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TY - JOUR

T1 - P-Aminobenzoate synthesis in Escherichia coli

T2 - Purification and characterization of PabB as aminodeoxychorismate synthase and enzyme X as aminodeoxychorismate lyase

AU - Ye, Qizhuang

AU - Liu, Jun

AU - Walsh, Christopher T.

PY - 1990

Y1 - 1990

N2 - The Escherichia coli pabA and pabB genes have been overexpressed separately and in tandem. Using purified PabB, we have confirmed the recent suggestion that PabB needs an additional protein, enzyme X, to convert chorismate and NH3 to p-aminobenzoate (PABA). With chorismate and NH3, pure PabB generates an intermediate presumed to be 4-amino-4-deoxychorismate based upon UV/visible spectroscopy and enzymatic and nonenzymatic transformations. The PabB-catalyzed interconversion of chorismate and isolated aminodeoxychorismate is readily reversible. With pure PabB as a stoichiometric assay reagent, enzyme X was purified ≈800-fold to near homogeneity as an apparent homodimer of 50 kDa from E. coli. Enzyme X shows no activity on chorismate but quantitatively converts the preformed aminodeoxychorismate into p-aminobenzoate and pyruvate, acting thereby as an aminodeoxychorismate lyase.

AB - The Escherichia coli pabA and pabB genes have been overexpressed separately and in tandem. Using purified PabB, we have confirmed the recent suggestion that PabB needs an additional protein, enzyme X, to convert chorismate and NH3 to p-aminobenzoate (PABA). With chorismate and NH3, pure PabB generates an intermediate presumed to be 4-amino-4-deoxychorismate based upon UV/visible spectroscopy and enzymatic and nonenzymatic transformations. The PabB-catalyzed interconversion of chorismate and isolated aminodeoxychorismate is readily reversible. With pure PabB as a stoichiometric assay reagent, enzyme X was purified ≈800-fold to near homogeneity as an apparent homodimer of 50 kDa from E. coli. Enzyme X shows no activity on chorismate but quantitatively converts the preformed aminodeoxychorismate into p-aminobenzoate and pyruvate, acting thereby as an aminodeoxychorismate lyase.

KW - Chorismate

KW - Folate biosynthesis

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