Tandem use of selenocysteine: adaptation of a selenoprotein glutaredoxin for reduction of selenoprotein methionine sulfoxide reductase

Title
Tandem use of selenocysteine: adaptation of a selenoprotein glutaredoxin for reduction of selenoprotein methionine sulfoxide reductase
Author(s)
김화영김문정[김문정]이병천[이병천]정재호[정재호]이공주[이공주]황광연[황광연]Gladyshev VN[Gladyshev VN]
Keywords
ESCHERICHIA-COLI; THIOREDOXIN REDUCTASE; INSERTION; SECIS; MECHANISM; GLUTATHIONE; SELENIUM; MAMMALS; ENZYME; GENE
Issue Date
201103
Publisher
WILEY-BLACKWELL
Citation
MOLECULAR MICROBIOLOGY, v.79, no.5, pp.1194 - 1203
Abstract
P>Several engineered selenocysteine (Sec)-containing glutaredoxins (Grxs) and their enzymatic properties have been reported, but natural selenoprotein Grxs have not been previously characterized. We expressed a bacterial selenoprotein Grx from Clostridium sp. (also known as Alkaliphilus oremlandii) OhILAs in Escherichia coli and characterized this selenoenzyme and its natural Cys homologues in Clostridium and E. coli. The selenoprotein Grx had a 200-fold higher activity than its Sec-to-Cys mutant form, suggesting that Sec is essential for catalysis by this thiol-disulfide oxidoreductase. Kinetic analysis also showed that the selenoprotein Grx had a 10-fold lower K(m) than Cys homologues. Interestingly, this selenoenzyme efficiently reduced a Clostridium selenoprotein methionine sulfoxide reductase A (MsrA), suggesting that it is the natural reductant for the protein that is not reducible by thioredoxin, a common reductant for Cys-containing MsrAs. We also found that the selenoprotein Grx could not efficiently reduce a Cys version of Clostridium MsrA, whereas natural Clostridium and E. coli Cys-containing Grxs, which efficiently reduce Cys-containing MsrAs, poorly acted on the selenoprotein MsrA. This specificity for MsrA reduction could explain why Sec is utilized in Clostridium Grx and more generally provides a novel example of the use of Sec in biological systems.
URI
http://hdl.handle.net/YU.REPOSITORY/25548http://dx.doi.org/10.1111/j.1365-2958.2010.07500.x
ISSN
0950-382X
Appears in Collections:
의과대학 > 생화학.분자생물학교실 > Articles
Files in This Item:
There are no files associated with this item.
Export
RIS (EndNote)
XLS (Excel)
XML


qrcode

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

BROWSE