HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 276, Issue 23, 20136-20143, June 8, 2001

This Article Full Text Full Text (PDF) All Versions of this Article: 276/23/20136    most recent M101349200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Espinosa, A. Articles by Stanley, S. L. Search for Related Content PubMed PubMed Citation Articles by Espinosa, A. Articles by Stanley, S. L., Jr. Social Bookmarking                      What's this?

The Bifunctional Entamoeba histolytica Alcohol Dehydrogenase 2 (EhADH2) Protein Is Necessary for Amebic Growth and Survival and Requires an Intact C-terminal Domain for Both Alcohol Dehydrogenase and Acetaldehyde Dehydrogenase Activity^*

Avelina Espinosa^§, Le Yan, Zhi Zhang, Lynne Foster, David Clark^¶, Ellen Li, and Samuel L. Stanley Jr.^§**

From the Departments of  Medicine, ^§ Molecular Microbiology, and  Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri 63110 and the ^¶ Department of Microbiology, Southern Illinois University, Carbondale, Illinois 62901

The intestinal protozoan pathogen Entamoeba histolytica lacks mitochondria and derives energy from the fermentation of glucose to ethanol with pyruvate, acetyl enzyme Co-A, and acetaldehyde as intermediates. A key enzyme in this pathway may be the 97-kDa bifunctional E. histolytica alcohol dehydrogenase 2 (EhADH2), which possesses both alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase activity (ALDH). EhADH2 appears to be a fusion protein, with separate N-terminal ALDH and C-terminal ADH domains. Here, we demonstrate that EhADH2 expression is required for E. histolytica growth and survival. We find that a mutant EhADH2 enzyme containing the C-terminal 453 amino acids of EhADH2 has ADH activity but lacks ALDH activity. However, a mutant consisting of the N-terminal half of EhADH2 possessed no ADH or ALDH activity. Alteration of a single histidine to arginine in the putative active site of the ADH domain eliminates both ADH and ALDH activity, and this mutant EhADH2 can serve as a dominant negative, eliminating both ADH and ALDH activity when co-expressed with wild-type EhADH2 in Escherichia coli. These data indicate that EhADH2 enzyme is required for E. histolytica growth and survival and that the C-terminal ADH domain of the enzyme functions as a separate entity. However, ALDH activity requires residues in both the N- and C-terminal halves of the molecule.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				A. Espinosa, D. Clark, and S. L. Stanley Jr Entamoeba histolytica alcohol dehydrogenase 2 (EhADH2) as a target for anti-amoebic agents J. Antimicrob. Chemother., July 1, 2004; 54(1): 56 - 59. [Abstract] [Full Text] [PDF]

				P. Echave, J. Tamarit, E. Cabiscol, and J. Ros Novel Antioxidant Role of Alcohol Dehydrogenase E from Escherichia coli J. Biol. Chem., August 8, 2003; 278(32): 30193 - 30198. [Abstract] [Full Text] [PDF]