Characterization of a monothiol glutaredoxin encoded by Chlorella virus PBCV-1.
Annotation of the 330-kb Chlorella virus PBCV-1 genome identified a 237 nucleotide gene (a438l) that codes for a protein with approximately 35% amino acid identity to glutaredoxins (Grx) found in other organisms. The PBCV-1 protein resembles classical Grxs in both size (9 kDa) and location of the active site (N-terminus). However, the PBCV-1 Grx is unusual because it contains a monothiol active site (CPYS) rather than the typical dithiol active site (CPYC). To examine this unique active site, four site-specific mutants (CPYC, CPYA, SPYC, and SPYS) were constructed to determine if the N-terminal cysteine is necessary for enzyme activity. Wild type and both mutants containing N-terminal cysteines catalyzed the reduction of disulfides in a coupled system with GSH, NADPH, and glutathione reductase. However, both mutants with an altered N-terminal cysteine were inactive. The grx gene is common in the Chlorella viruses. Molecular phylogenetic analyses of the PBCV-1 enzyme support its relatedness to those from other Chlorella viruses and yet demonstrate the divergence of the Grx molecule.
Fitzgerald
Lisa A
LA
Department of Plant Pathology, University of Nebraska, Lincoln, NE 68583, USA.
Zhang
Yuanzheng
Y
Lewis
Gentry
G
Van Etten
James L
JL
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D020134:Catalytic Domain; D002708:Chlorella / Q000821:virology*; D054477:Glutaredoxins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D017862:Phycodnaviridae / Q000201:enzymology* / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*
D054477:Glutaredoxins; D014764:Viral Proteins
J Mol Biol. 1994 Feb 4;235(5):1585-97
8107093
Biochemistry. 2009 Feb 17;48(6):1410-23
19166312
Virology. 1984 Apr 30;134(2):443-9
18639814
Exp Eye Res. 1996 Oct;63(4):433-41
8944550
Cell Mol Life Sci. 2007 Jun;64(12):1518-30
17415523
Methods Enzymol. 1995;252:283-92
7476363
Structure. 1995 Mar 15;3(3):245-50
7788290
Virology. 2007 Feb 20;358(2):472-84
17027058
Virology. 2007 Feb 20;358(2):459-71
17023017
Virology. 2007 Jun 5;362(2):350-61
17276475
Virology. 2001 Jul 5;285(2):332-45
11437667
Virus Res. 2006 Apr;117(1):156-84
16494962
Cell Mol Life Sci. 2004 Jun;61(11):1266-77
15170506
Virology. 1983 Apr 15;126(1):117-25
18638936
Science. 2004 Nov 19;306(5700):1344-50
15486256
Methods Enzymol. 2002;347:286-96
11898418
Biochemistry. 1991 Jun 25;30(25):6088-97
1829380
Biochemistry. 1992 Sep 29;31(38):9288-93
1390715
Photosynth Res. 2006 Sep;89(2-3):127-40
16915356
Biochemistry. 1991 Sep 10;30(36):8883-91
1888746
Annu Rev Microbiol. 1999;53:447-94
10547698
Photosynth Res. 2006 Sep;89(2-3):225-45
17089213
Virology. 1981 Sep;113(2):704-11
18635089
Photosynth Res. 2004;79(3):305-18
16328797
J Virol. 2001 Dec;75(23):11720-34
11689653
Virology. 1996 Sep 15;223(2):303-17
8806566
Biochim Biophys Acta. 2008 Nov;1780(11):1304-17
18621099
J Biol Chem. 1997 Apr 25;272(17):11236-43
9111025
J Biol Chem. 1951 Nov;193(1):265-75
14907713