Linked Life Data

20947511

Source:http://linkedlifedata.com/resource/pubmed/id/20947511

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
2010-12-14
pubmed:abstractText
Steady exposure to environmental arsenic has led to the evolution of vital cellular detoxification mechanisms. Under aerobic conditions, a two-step process appears most common among microorganisms involving reduction of predominant, oxidized arsenate (H(2)As(V)O(4)(-)/HAs(V)O(4)(2-)) to arsenite (As(III)(OH)(3)) by a cytosolic enzyme (ArsC; Escherichia coli type arsenate reductase) and subsequent extrusion via ArsB (E. coli type arsenite transporter)/ACR3 (yeast type arsenite transporter). Here, we describe novel fusion proteins consisting of an aquaglyceroporin-derived arsenite channel with a C-terminal arsenate reductase domain of phosphotyrosine-phosphatase origin, providing transposable, single gene-encoded arsenate resistance. The fusion occurred in actinobacteria from soil, Frankia alni, and marine environments, Salinispora tropica; Mycobacterium tuberculosis encodes an analogous ACR3-ArsC fusion. Mutations rendered the aquaglyceroporin channel more polar resulting in lower glycerol permeability and enhanced arsenite selectivity. The arsenate reductase domain couples to thioredoxin and can complement arsenate-sensitive yeast strains. A second isoform with a nonfunctional channel may use the mycothiol/mycoredoxin cofactor pool. These channel enzymes constitute prototypes of a novel concept in metabolism in which a substrate is generated and compartmentalized by the same molecule. Immediate diffusion maintains the dynamic equilibrium and prevents toxic accumulation of metabolites in an energy-saving fashion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/ACR3 protein, S cerevisiae, http://linkedlifedata.com/resource/pubmed/chemical/Aquaglyceroporins, http://linkedlifedata.com/resource/pubmed/chemical/ArsAB ATPase, E Coli, http://linkedlifedata.com/resource/pubmed/chemical/Arsenates, http://linkedlifedata.com/resource/pubmed/chemical/Escherichia coli Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Ion Pumps, http://linkedlifedata.com/resource/pubmed/chemical/Membrane Transport Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Multienzyme Complexes, http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Fusion Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Saccharomyces cerevisiae Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Teratogens, http://linkedlifedata.com/resource/pubmed/chemical/arsenic acid
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1083-351X
pubmed:author
pubmed:issnType
Electronic
pubmed:day
17
pubmed:volume
285
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
40081-7
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Novel channel enzyme fusion proteins confer arsenate resistance.
pubmed:affiliation
Department of Pharmaceutical and Medicinal Chemistry, Christian-Albrechts-Universität zu Kiel, 24118 Kiel, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't