Primary Structure and Phylogenetic Relationships of a Malate Dehydrogenase Gene from Giardia lamblia |
| |
Authors: | Andrew J. Roger Hilary G. Morrison Mitchell L. Sogin |
| |
Affiliation: | (1) Josephine Bay Paul Center for Comparative Molecular Biology and Evolution, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA 02543-1015, USA, US |
| |
Abstract: | The lactate and malate dehydrogenases comprise a complex protein superfamily with multiple enzyme homologues found in eubacteria, archaebacteria, and eukaryotes. In this study we describe the sequence and phylogenetic relationships of a malate dehydrogenase (MDH) gene from the amitochondriate diplomonad protist, Giardia lamblia. Parsimony, distance, and maximum-likelihood analyses of the MDH protein family solidly position G. lamblia MDH within a eukaryote cytosolic MDH clade, to the exclusion of chloroplast, mitochondrial, and peroxisomal homologues. Furthermore, G. lamblia MDH is specifically related to a homologue from Trichomonas vaginalis. This MDH topology, together with published phylogenetic analyses of β-tubulin, chaperonin 60, valyl-tRNA synthetase, and EF-1α, suggests a sister-group relationship between diplomonads and parabasalids. Since these amitochondriate lineages contain genes encoding proteins which are characteristic of mitochondria and α-proteobacteria, their shared ancestry suggests that mitochondrial properties were lost in the common ancestor of both groups. Received: 14 September 1998 / Accepted: 29 December 1998 |
| |
Keywords: | :Giardia lamblia— Diplomonads — Malate dehydrogenase — Protein phylogeny — Amitochondriate protist |
本文献已被 PubMed SpringerLink 等数据库收录! |
|