Regulatory Divergence of Aspartate Transcarbamoylase from the Pseudomonads Metadata

Title

• Main Title Regulatory Divergence of Aspartate Transcarbamoylase from the Pseudomonads

Creator

• Author: Linscott, Andrea J. (Andrea Jane)
  Creator Type: Personal

Contributor

• Chair: O'Donovan, Gerard A.
  Contributor Type: Personal
  Contributor Info: Major Professor
• Committee Member: Shanley, Mark Stephen
  Contributor Type: Personal
• Committee Member: Benjamin, Robert C.
  Contributor Type: Personal
• Committee Member: Goven, Arthur James, 1950-
  Contributor Type: Personal

Publisher

• Name: University of North Texas
  Place of Publication: Denton, Texas

Date

• Creation: 1996-12

Language

• English

Description

• Content Description: Aspartate transcarbamoylase (ATCase) was purified from 16 selected bacterial species including existing Pseudomonas species and former species reassigned to new genera. An enormous diversity was seen among the 16 enzymes with each class of ATCase being represented. The smallest class, class C, with a catalytically active homotrimer, at 100 kDa, was found in Bacillus and other Gram positive bacteria. In this report, the ATCases from the Gram negatives, Shewanella putrefaciens and Stenotrophomonas maltophilia were added to class C membership. The enteric bacteria typify class B ATCases at 310 kDa, with a dodecameric structure composed of two catalytic trimers coupled to three regulatory dimers. A key feature of class B ATCases is the dissociability of the holoenzyme into regulatory and catalytic subunits which were enzymatically active. In this report, the ATCase from Pseudomonas indigofera was added to class B ATCases. The largest class, at 480 kDa, class A, contains the fluorescent Pseudomonas including most members of the 16S rRNA homology group I. Two polypeptides are produced from overlapping pyrBC' genes. The former, pyrB, encodes a 34 kDa catalytic polypeptide while pyrC' encodes a 45 kDa dihydroorotase-like polypeptide. Two non active trimers are made from six 34 kDa chains which are cemented by six 45 kDa chains to form the active dodecameric structure. Dissociation of the holoenyzme into its separate active subunits has not been possible. In this report, the ATCases from Comamonas acidovorans and C. testosteroni, were added to the class A enzymes. An even larger class of ATCase than class A at 600 kDa was discovered in Burkholderia cepacia. Stoichiometric measurements predict a dodecamer of six 39 kDa polypeptides and six 60 kDa polypeptides. Unlike other large pseudomonads ATCases, the enzyme from B. cepacia was dissociable into smaller active forms. Both the holoenzyme and its dissociated forms were regulated by nucleotide effectors. A new class of ATCase was proposed for B. cepacia type enzymes.
• Physical Description: xvi, 210 leaves : ill.

Subject

• Keyword: aspartate transcarbamoylase
• Keyword: pseudomonads
• Keyword: biology
• Library of Congress Subject Headings: Pyrimidine nucleotides -- Metabolism.
• Library of Congress Subject Headings: Pseudomonas.

Collection

• Name: UNT Theses and Dissertations
  Code: UNTETD

Institution

• Name: UNT Libraries
  Code: UNT

Rights

• Rights Access: public
• Rights License: copyright
• Rights Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.
• Rights Holder: Linscott, Andrea J. (Andrea Jane)

Resource Type

• Thesis or Dissertation

Format

• Text

Identifier

• Call Number: 379 N81d no.4416
• UNT Catalog No.: b2029260
• Accession or Local Control No: 1002726737-linscott
• Archival Resource Key: ark:/67531/metadc277625

Degree

• Degree Level: Doctoral
• Degree Grantor: University of North Texas
• Degree Name: Doctor of Philosophy
• Academic Department: Department of Biological Sciences
• Degree Discipline: Biology

Note