Entamoeba histolytica:: Observations on metabolism based on the genome sequence

The sequencing of the genome of Entamoeba histolytica has allowed a reconstruction of its metabolic pathways, many of which are unusual for a eukaryote. Based on the genome sequence, it appears that amino acids may play a larger role than previously thought in energy metabolism, with roles in both ATP synthesis and NAD regeneration. Arginine decarboxylase may be involved in survival of E histolytica during its passage through the stomach. The usual pyrimidine synthesis pathway is absent, but a partial pyrimidine degradation pathway could be part of a novel pyrimidine synthesis pathway. Ribonucleotide reductase was not found in the E histolytica genome, but it was found in the close relatives Entamoeba invadens and Entamoeba moshkovskii, suggesting a recent loss from E histolytica. The usual eukaryotic glucose transporters are not present, but members of a prokaryotic monosaccharide transporter family are present. (c) 2005 Elsevier Inc. All rights reserved.