Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the 'hotspot' topogenic signal model.
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Kendall G, Wilderspin AF, Ashall F, Miles MA, Kelly JM
Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase does not conform to the 'hotspot' topogenic signal model.
EMBO J. 1990 Sep;9(9):2751-8.
- PubMed ID
- 2167831 [ View in PubMed]
- Abstract
The genes which encode glycosomal glyceraldehyde-phosphate dehydrogenase (gGAPDH) of Trypanosoma cruzi are arranged as a tandemly repeated pair on a single chromosome and are identical at the level of nucleotide sequence. They are separated by an intergenic region which contains a 317 base pair sequence with the properties of a retroposon. The genes express a 1.5 kb mRNA and a 38 kd protein. The amino acid sequence contains features characteristic of glycosomal enzymes such as peptide insertions and a C-terminal extension. However, T. cruzi gGAPDH lacks one of the positively charged 'hotspot' motifs which have been proposed as topogenic signals for import into the glycosome, a unique microbody-like organelle. Molecular modelling of the T. cruzi and T. brucei enzymes suggests that neither structure would fulfil the requirements of the 'hotspot' glycosomal import model.