Linked Life Data

18492666

Source:http://linkedlifedata.com/resource/pubmed/id/18492666

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
2008-7-14
pubmed:abstractText
Overexpression in Escherichia coli of a tau (U) class glutathione transferase (GST) from maize (Zea mays L.), termed ZmGSTU1, caused a reduction in heme levels and an accumulation of porphyrin precursors. This disruption was highly specific, with the expression of the closely related ZmGSTU2 or other maize GSTs having little effect. Expression in E. coli of a series of chimeric ZmGSTU1/ZmGSTU2 proteins identified domains responsible for disrupting porphyrin metabolism. In addition to known heme precursors, expression of ZmGSTU1 led to the accumulation of a novel glutathione conjugate of harderoporphyrin(ogen) (2,7,12,18-tetramethyl-3-vinylporphyrin-8,13,17-tripropionic acid). Using the related protoporphyrinogen as a substrate, conjugation could be shown to occur on one vinyl group and was actively catalyzed by the ZmGSTU. In plant transgenesis studies, the ZmGSTUs did not perturb porphyrin metabolism when expressed in the cytosol of Arabidopsis or tobacco. However, expression of a ZmGSTU1-ZmGSTU2 chimera in the chloroplasts of tobacco resulted in the accumulation of the harderoporphyrin(ogen)-glutathione conjugate observed in the expression studies in bacteria. Our results show that the well known ability of GSTs to act as ligand binding (ligandin) proteins of porphyrins in vitro results in highly specific interactions with porphyrinogen intermediates, which can be demonstrated in both plants and bacteria in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
283
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20268-76
pubmed:meshHeading
pubmed:year
2008
pubmed:articleTitle
Binding and glutathione conjugation of porphyrinogens by plant glutathione transferases.
pubmed:affiliation
Centre for Bioactive Chemistry, School of Biological and Biomedical Sciences, Durham University, Durham, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't