A genetic analysis of in vivo selenate reduction by Salmonella enterica serovar Typhimurium LT2 and Escherichia coli K12

TY - JOUR

T1 - A genetic analysis of in vivo selenate reduction by Salmonella enterica serovar Typhimurium LT2 and Escherichia coli K12

A1 - Guymer,David

A1 - Maillard,Julien

A1 - Sargent,Frank

AU - Guymer,David

AU - Maillard,Julien

AU - Sargent,Frank

PY - 2009/6

Y1 - 2009/6

N2 - <p>The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In Salmonella enterica serovar Typhimurium and Escherichia coli many Tat substrates are known or predicted to bind a molybdenum cofactor in the cytoplasm prior to export. In the case of N- and S-oxide reductases, co-ordination of molybdenum cofactor insertion with protein export involves a 'Tat proofreading' process where chaperones of the TorD family bind the signal peptides, thus preventing premature export. Here, a genetic approach was taken to determine factors required for selenate reductase activity in Salmonella and E. coli. It is reported for both biological systems that an active Tat translocase and a TorD-like chaperone (DmsD) are required for complete in vivo reduction of selenate to elemental red selenium. Further mutagenesis and in vitro biophysical experiments implicate the Salmonella ynfE gene product, and the E. coli YnfE and YnfF proteins, as putative Tat-targeted selenate reductases.</p>

AB - <p>The twin-arginine transport (Tat) system is dedicated to the translocation of folded proteins across the bacterial cytoplasmic membrane. Proteins are targeted to the Tat system by signal peptides containing a twin-arginine motif. In Salmonella enterica serovar Typhimurium and Escherichia coli many Tat substrates are known or predicted to bind a molybdenum cofactor in the cytoplasm prior to export. In the case of N- and S-oxide reductases, co-ordination of molybdenum cofactor insertion with protein export involves a 'Tat proofreading' process where chaperones of the TorD family bind the signal peptides, thus preventing premature export. Here, a genetic approach was taken to determine factors required for selenate reductase activity in Salmonella and E. coli. It is reported for both biological systems that an active Tat translocase and a TorD-like chaperone (DmsD) are required for complete in vivo reduction of selenate to elemental red selenium. Further mutagenesis and in vitro biophysical experiments implicate the Salmonella ynfE gene product, and the E. coli YnfE and YnfF proteins, as putative Tat-targeted selenate reductases.</p>

KW - Enteric bacteria

KW - Bacterial respiration

KW - Twin-arginine translocation pathway

KW - Molybdo-enzymes

KW - Selenate reductase

KW - Molecular chaperone

KW - Mutagenesis

KW - Isothermal titration calorimetry

KW - ENTEROBACTER-CLOACAE SLD1A-1

KW - DIMETHYL-SULFOXIDE REDUCTASE

KW - SIGNAL PEPTIDE

KW - NITRATE REDUCTASE

KW - PROOFREADING CHAPERONE

KW - TRANSLOCATION PATHWAY

KW - DMSO REDUCTASE

KW - EXPORT PATHWAY

KW - UBIE GENE

KW - COLI

U2 - 10.1007/s00203-009-0478-7

DO - 10.1007/s00203-009-0478-7

M1 - Article

JO - Archives of Microbiology

JF - Archives of Microbiology

SN - 0302-8933

IS - 6

VL - 191

SP - 519

EP - 528

ER -