Analysis of four ENU induced triosephosphate isomerase mutants with reduced enzyme activity in mus musculus
- Lawrence Livermore National Laboratory, CA (United States)
- Institut fuer Saugetiergenetik, Neuherberg (Germany)
Four independent ENU induced mutations associated with a 50% loss of triosephosphate isomerase (TPI) activity have been identified in mouse germinal mutation experiments. Genomic PCR amplification products using primers homologous to the intron regions of the TPI gene from control and mutant mice were directly sequenced to determine the molecular lesion in each of these mutants. Mutants Tpi*M-1NEU and Tpi*M-2NEU carried the same T:A to A:T transversion, resulting in a Leu to Glu substitution at residue 192. Residue 192 is located in {alpha}-helix H6, on the surface of the protein. Analysis of the Tpi*M-3NEU allele revealed an A:T to C:G transversion changing the stop codon to Cys, resulting in the addition of 19 amino acids. The fourth mutant, Tpi*M-4NEU, was another T:A to A:T transversion resulting in a Leu to Glu substitution, this time at residue 162. This mutation is situated next to a region conserved in all TPI genes sequenced. It is placed at the beginning at {beta}-strand B6 in the immediate vicinity of the active site residue Glu 165. These mutants provide insight into the mechanism of ENU mutagenesis and can serve as models for structure-function studies of the interesting enzyme where most of the variants are null variants rather than electromorphs.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 88936
- Report Number(s):
- CONF-9405324--
- Journal Information:
- Environmental and Molecular Mutagenesis, Journal Name: Environmental and Molecular Mutagenesis Journal Issue: Suppl.23 Vol. 23; ISSN 0893-6692; ISSN EMMUEG
- Country of Publication:
- United States
- Language:
- English
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