Table 1.

Small Proteins of the Thioredoxin Protein Family Identified in African Trypanosomes

	T. brucei protein
Properties	2-C-Grx1a	2-C-Grx2a	TXNb	Trxc	1-C-Grx1d	1-C-Grx2d	1-C-Grx3d
Gene Accession N°	Tb11.47.0012	Tb927.1.1770	Tb927.3.3780	Tb09.160.2020	AJ619696	AM489503	AM489504
Subunit molecular mass (kDa)	10,576	12,152	15,891	12,135	15,931	12,595	24,624
Oligomeric structure (apo/holo)	Monomer/Dimeric ISC	Monomer	Monomer	Monomer	Dimer / Dimeric ISC	Monomer / Dimeric ISC	Monomer / Dimeric ISC
3D-structure (PDB code)	NDe	ND	1O73	1R26	2LTK	ND	ND
Active site motif	CPYC	CQFC	CPPC	CGPC	CAYS	CGFT	CGFT
Putative in vivo reducing agent	T(SH)2	T(SH)2	T(SH)2	T(SH)2	T(SH)2/TXN	ND	ND
Subcellular localization	cytosol	mitochondrial	cytosol	cytosolf	mitochondrial	mitochondrial	cytosolf
Putative function	Protein deglutationylation Reduction of GSSG by T(SH)2 Iron sulfur metabolism	Protein disulfide reduction Protein deglutationylation	Protein disulfide reduction	Protein disulfide reduction	ISC metabolism	unknown	unknown
Indispensability under culture conditions	no	yes	yes	no	yes	ND	ND
Total cellular concentration (μM)g	about 2	0.1–0.4	80–90	≪1	5–30	<0.5	2–6

Data taken from references ^a12; ^b15, 53; ^c29, 70, 78, 79; ^d16, 27, 55a, 58. ^eND, not determined, ^fsuggested localization based on the absence of a putative targeting signal, ^g in the mammalian bloodstream form. The light gray shading refers to biophysical and structural properties. The dark gray shading denotes biochemical and biological functions of the proteins.