Vibrio cholerae thiol peroxidase-glutaredoxin fusion is a 2-Cys TSA/AhpC subfamily acting as a lipid hydroperoxide reductase.
Recently, novel hybrid thiol peroxidase (TPx) proteins fused with a glutaredoxin (Grx) were found from some pathogenic bacteria, cyanobacteria, and anaerobic sulfur-oxidizing phototroph. The phylogenic tree analysis that was constructed from the aligned sequences showed two major branches. Haemophilus influenzae TPx.Grx was grouped in one branch as a 1-Cys subfamily of the thiol-specific antioxident protein/AhpC family. Most TPx.Grx proteins, including Vibrio cholerae TPx.Grx, were grouped in the 2-Cys subfamily. To explain the existence of two subgroups in novel hybrid TPx proteins, we have compared the kinetics given by V. cholerae TPx.Grx, H. influenzae TPx.Grx, their separated TPx domains, and a set of mutants devoid of the redox-active cysteines. The kinetic study described here demonstrates clearly that V. cholerae TPx.Grx is a 2-Cys TPx subfamily. For the first time, we also demonstrate the lipid peroxidase activity of V. cholerae TPx.Grx fusion and suggest the in vivo function of 2-Cys TPx.Grx fusion serving as a lipid peroxidase.
Cha
Mee-Kyung
MK
Department of Biochemistry, Paichai University, Taejon 302-735, Republic of Korea.
Hong
Seung-Keun
SK
Lee
Dong-Suk
DS
Kim
Il-Han
IH
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D054477:Glutaredoxins; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010544:Peroxidases / Q000737:chemistry / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014734:Vibrio cholerae / Q000201:enzymology*
D001426:Bacterial Proteins; D017931:DNA Primers; D054477:Glutaredoxins; D011506:Proteins; D011993:Recombinant Fusion Proteins; D010088:Oxidoreductases; D010544:Peroxidases