View : 13 Download: 0

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
Authors
Kim M.-J.Lee B.C.Jeong J.Lee K.-J.Hwang K.Y.Gladyshev V.N.Kim H.-Y.
Ewha Authors
이공주
SCOPUS Author ID
이공주scopus
Issue Date
2011
Journal Title
Molecular Microbiology
ISSN
0950-382XJCR Link
Citation
vol. 79, no. 5, pp. 1194 - 1203
Indexed
SCI; SCIE; SCOPUS WOS scopus
Abstract
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 Km 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. © 2011 Blackwell Publishing Ltd.
DOI
10.1111/j.1365-2958.2010.07500.x
Appears in Collections:
약학대학 > 약학과 > Journal papers
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