Table 2.

Potential Phosphorylation Sites of Human Grx Enzymes

Grx isoform	Residue (FASTA)	Kinase	Probability score	aLocation (relative to active site)
Human Grx1	S34	DNAPK	0.6	Opposite end of α-helix 2
	S88	PKC	0.66	Neighboring α-helix 4
Human Grx2	S16	General	0.73	b
	S20	General, PKA	0.91, 0.68	b
	S39	General	0.69	b
	S48	General	0.99	b
	S73	PKC	0.61	Facing active site (β-sheet 1)
	T81	PKC	0.8	Immediately after active site (α-helix 2)
	Y113	General	0.73	Opposite side of protein(α-helix 3)
	T137	General, PKC	0.9, 0.84	Neighboring α-helix(α-helix 4)
	S158	General, PKC	0.9, 0.84	b
Human Grx5	S41	General	0.69	c
	S156	General	0.87	c

FASTA sequences of human Grx1, Grx2, and Grx5 were entered into NetPhos 2.0 (12) and NetPhosK 1.0 (13) search engines to identify potential phosphorylation sites. Sites with probability scores ≥0.6 are included.

DNAPK, DNA-dependent protein kinase; PKC, protein kinase C; PKG, cyclic GMP–dependent protein kinase.

^aThe hydroxyl groups of all of the indicated residues are solvent exposed and outward facing, with the exception of Grx2 T137, which faces the protein interior.

^bNot included in published x-ray structure.

^cNo structural information available.