rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Overexpression, purification, and characterization of the Pseudomonas denitrificans and Salmonella typhimurium gene products in vitamin B12 biosynthesis, structural analysis of vitamin B12 intermediates, and enzymatic synthesis of factor S3
  name:
    name part: Ozaki, Shin-Ichi.
    role:
      role term: creator
  name:
    name part: Scott, A. I.
    role:
      role term: degree supervisor.
  name:
    name part: Fitzpatrick, P. F.
    role:
      role term: degree committee member.
  name:
    name part: Hogg, J. L.
    role:
      role term: degree committee member.
  name:
    name part: Kelly, J. W.
    role:
      role term: degree committee member.
  name:
    name part: Texas A & M University
    role:
      role term: degree granting institution.
  type of resource: text
  genre: bibliography
  genre: Academic theses
  origin info:
    place:
      place term: xx
    date issued: 1992
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: print
    extent: xiii, 99 leaves : illustrations ; 28 cm
  abstract: Some of the Pseudomonas denitrificans cob and the Salmonella typhimurium cbi genes involved in vitamin B12 biosynthesis were overexpressed in the heterologous E. coli system and purified. The functions of P. denitrificans cobI and S. typhimurium cbiL gene products were defined as S-adenosyl methionine dependent methyltransferases catalyzing C-20 methylation of precorrin-2 respectively. The S. typhimurium cbiA gene product was characterized as adenosyl triphosphate dependent cobyrinic acid a,c-diamide synthase. It was proved that the S. typhimurium cbiF gene product catalyzes C-16 methylation of trimethylpyrrocorphin I to afford metal-free factor S3. Zinc insertion into the macrocycle took place non-enzymatically to produce factor S3, the zinc complex of a tetramethylated derivative of uroporphyrinogen I. The structures of precorrin-2, precorrin-3, factor II, factor III (intermediates of vitamin B12 biosynthesis), trimethylpyrrocorphin I (intermediate of factor S3 biosynthesis), and factor S3 derived from various 13C-enriched isotopomers of porphobilinogens were elucidated by 13C NMR. Successive addition of the electron donating methyl groups resulted in the changes in the conjugated array of C=C and C=N bonds of the main macrocycle, which were revealed in the NMR spectra. The differences between precorrin-2 and -3 or factor II and III in their 13C NMR spectra were attributed to the electron distribution of the macrocycle and the disruption of symmetry by C-20 methylation of precorrin-2. Careful consideration of line widths and the chemical shifts of their 13C signals indicate that precorrin-2 and factor II have time-averaged structures but that precorrin-3 and factor III have relatively fixed conjugation systems.
  note: Vita.
  note: "Major subject: Chemistry."
  note: Includes bibliographical references.
  note: Ph. D. Texas A & M University 1992
  subject:
    topic: Pseudomonas
  subject:
    topic: Salmonella typhimurium
  subject:
    topic: Biochemical genetics
  subject:
    topic: Enzymatic analysis
  subject:
    topic: Vitamin B12
  subject:
    topic: Major chemistry
  identifier: http://proxy.library.tamu.edu/login
  related item:
    location:
      url: http://proxy.library.tamu.edu/login
  record info:
    record content source: TXA
    record creation date: 941116
    record change date: 20200904152632.0
    record identifier: in00001204523
    language of cataloging:
      language term: eng