Novel Protein-disulfide Isomerases from the Early-diverging Protist Giardia lamblia

Genomic minimalism in the early diverging intestinal parasite Giardia lamblia.

The genome of the eukaryotic protist Giardia lamblia, an important human intestinal parasite, is compact in structure and content, contains few introns or mitochondrial relics, and has simplified machinery for DNA replication, transcription, RNA processing, and most metabolic pathways. Protein kinases comprise the single largest protein class and reflect Giardia's requirement for a complex sign...

Core histones of the amitochondriate protist, Giardia lamblia.

Genes coding for the core histones H2a, H2b, H3, and H4 of Giardia lamblia were sequenced. A conserved organism- and gene-specific element, GRGCGCAGATTTVGG, was found upstream of the coding region in all core histone genes. The derived amino acid sequences of all four histones were similar to their homologs in other eukaryotes, although they were among the most divergent members of this protein...

Identification of a Novel Microtubule-Binding Protein in Giardia lamblia

Giardia lamblia is a protozoan that causes diarrheal diseases in humans. Cytoskeletal structures of Giardia trophozoites must be finely reorganized during cell division. To identify Giardia proteins which interact with microtubules (MTs), Giardia lysates were incubated with in vitro-polymerized MTs and then precipitated by ultracentifugation. A hypothetical protein (GL50803_8405) was identified...

Giardia Lamblia.

Functional Differences in Yeast Protein Disulfide Isomerases

PDI1 is the essential gene encoding protein disulfide isomerase in yeast. The Saccharomyces cerevisiae genome, however, contains four other nonessential genes with homology to PDI1: MPD1, MPD2, EUG1, and EPS1. We have investigated the effects of simultaneous deletions of these genes. In several cases, we found that the ability of the PDI1 homologues to restore viability to a pdi1-deleted strain...