. 2008 May;179(1):59–68. doi: 10.1534/genetics.107.086033

TABLE 2.

Orthologs of Fe–S cluster assembly proteins in Chlamydomonas, Arabidopsis, bacteria, and yeast

	C. reinhardtii	C. r. protein ID	A. thaliana	A. t. localization	A. t. AGI gene model	E. coli	Synechocystis	S. cerevisiae	Molecular functionor protein domain^a
ISC	NFS1	118253	NFS1	Mit	At5g65720	IscS	Slr0387	Nfs1	Cysteine desulfurase
	ISD11	184200	ISD11	Mit^b	At5g61220			Isd11	Unknown
	ISU1	187899	ISU1, -2, -3	Mit	At4g22220, At3g01020 At4g04080	IscU		Isu1, -2	Fe–S scaffold
	ISCA1	196772	Not annotated	Mit^b	At2g16710	IscA		Isa1, -2	Fe–S scaffold
	IBA57^c	187731^d	Not annotated	Mit^b	At4g12130				Unknown
	NFU2	205851^e 205852^e	NFU4, NFU5	Mit	At3g20970, At1g51390	NP_312283		Nfu1	Fe–S scaffold
	MFDX	154720	ADX1, -2 = MFDX1, -2	Mit	At4g05450	Fdx		Yah1	Ferredoxin
	ARH1	134840	ADXR = MFDR	Mit	At4g32360			Arh1	Reductase
	MNP1	133548	HCF101-L1	Mit^f	At4g19540	Mrp			P-loop NTPase^a
	Not specialized?^g		Not specialized?^g			HscA		Ssq1	Chaperone (HSP70)
	HSC20	144583	Not annotated	Mit^b	At5g06410	HscB		Jac1	Cochaperone
	MGE1	132633	Not annotated	Mit^b	At5g55200			Mge1	Nucleotide release factor
	FTX1	196778	FH	Mit	At4g03240	CyaY		Yfh1	Iron chaperone
	GRX5	195767	Not annotated	Mit^b	At3g15660	Grx		Grx5	Glutaredoxin
Export	CDS1^h	133289	ATM1	Mit	At4g28630			Atm1	Half ABC transporter
	ATM2	105113	ATM2	Mit	At4g28620			Atm1	Half ABC transporter
	ATM3	99736	ATM3 = STA1	Mit	At5g58270			Atm1	Half ABC transporter
	ERV1ⁱ	114232	ERV1	Mit	At1g49880			Erv1	Sulfhydryl oxidase
CIA	Absent		Absent			Mrp		Cfd1	P-loop NTPase^a
	MNP2	206480	HCF101-L2	Cytosol^f	At5g50960			Nbp35	P-loop NTPase^a
	IOP1 (HYD3)	206492^d	NAR1	Cytosol^b	At4g16440			Nar1	Hydrogenase-like^a
	CIA1	158085	Not annotated	Cytosol^b	At2g26060			Cia1	WD40 protein
SUF	SUFA	100292	SUFA = ISCA	Plastid	At1g10500	SufA	Slr1417		Fe–S scaffold
	SUFB	132600^d	SUFB = NAP1	Plastid	At4g04770	SufB	Slr0074		ABC/ATPase
	SUFC	289	SUFC = NAP7	Plastid	At3g10670	SufC	Slr0075		ABC/ATPase
	SUFD	154386	SUFD = NAP6	Plastid	At1g32500	SufD	Slr0076		ABC/ATPase
	SUFE	156669	SUFE1, -2, -3 (N-term.)^j	Plastid	At4g26500, At1g67810, At5g50210	SufE	Slr1419		Unknown
	SUFS	206481	NFS2 = CpNifS	Plastid	At1g08490	SufS/CsdB	Slr0077		Cysteine desulfurase
NFU	NFU1	206476	NFU1, -2, -3	Plastid	At4g01940, At5g49940, At4g25910	NP_312283	Ssl2667		Fe–S scaffold
	NFU3	188996	NFU1, -2, -3	Plastid			Ssl2667		Fe–S scaffold
HCF101	HCF101	102098^d	HCF101	Plastid	At3g24430		Slr0067		DUF59 + P-loop NTPase^a
Hydrogenase maturation	HYDEF	128256	Absent						Radical SAM + GTPase^a
	HYDG	196226	Absent						Radical SAM^a
Other	CSD2	167884	Absent				Sll0704		Cysteine desulfurase
	DFO1	206478	Not annotated		At1g68310				DUF59 (unknown)^a
	ISCA2	162474^d	Not annotated	Mit/plastid^b	At5g03905	ErpA?			Fe–S scaffold

Organisms: C. r., Chlamydomonas reinhardtii; A. t., the higher plant Arabidopsis thaliana; E. coli, the proteobacterium Escherichia coli; cyanobacterium Synechocystis sp. PCC 6803; and S. cerevisiae, Baker's yeast, Saccharomyces cerevisiae.

Function inferred from conserved protein domain(s). DUF59, domain of unknown function 59 (Pfam PF01883); radical SAM, radical S-adenosylmethionine enzyme.

Predicted.

IBA57, iron–sulfur cluster assembly factor for biotin synthase- and aconitase-like mitochondrial proteins, M_r 57 kDa. (Gelling et al. 2008).

The sequence is incomplete or not deemed correct because of annotation issues.

The two models are generated by alternative splicing, which appears to be conserved in Volvox. The significance of this remains to be investigated.

K. Bych and J. Balk, unpublished results.

The Hsp70 proteins HscA from E. coli and Ssq1 from yeast are specialized for Fe–S cluster assembly, but do not share the same genetic origin. The yeast Yarrowia lipolytica does not have a specialized Hsp70, and this situation may be the case for most eukaryotes (Schilke et al. 2006).

CDS1, Cadmium sensitive 1, is the only Chlamydomonas gene characterized experimentally (Hanikenne et al. 2005).

ⁱ

Two genes with high similarity to ERV1 are present in Chlamydomonas. This may reflect the situation in S. cerevisiae, where ERV1 is a sulfhydryl oxidase of the mitochondrial inner membrane space, whereas ERV2 resides in the endoplasmic reticulum.

In Arabidopsis, SUFE3 is a fusion protein of NADA and a SUFE domain (Murthy et al. 2007).