Display Settings:

Format

Send to:

Choose Destination
    J Biol Chem. 1989 Oct 5;264(28):16613-9.

    A cysteine-histidine-aspartate catalytic triad is involved in glutamine amide transfer function in purF-type glutamine amidotransferases.

    Source

    Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907.

    Abstract

    A family of four glutamine amidotransferases has a homologous glutamine amide transfer domain, designated purF-type, that is named after purF-encoded glutamine phosphoribosylpyrophosphate amidotransferase. The glutamine amide transfer domain of approximately 194 amino acid residues is at the NH2 terminus of the protein chain. Site-directed mutagenesis was used to replace several of the 9 invariant amino acids in the glutamine amide transfer domain of glutamine phosphoribosylpyrophosphate amidotransferase. The results indicate that a Cys1-His101-Asp29 catalytic triad is involved in the glutamine amide transfer function of this enzyme. The evidence suggests that His101 functions to increase the nucleophilicity of Cys1, which is used to form a glutamine-enzyme covalent intermediate. Asp29 has a role subsequent to formation of the covalent intermediate. The Cys-His-Asp catalytic triad is implicated in the glutamine amide transfer function of purF-type amidotransferases.

    PMID:
    2674138
    [PubMed - indexed for MEDLINE]

      Supplemental Content

      Icon for HighWire Press

      Save items

      loading

      Recent activity

      Your browsing activity is empty.

      Activity recording is turned off.

      Turn recording back on

      See more...
      Write to the Help Desk