Table 5.

Yeast DNA helicases. nd, Not determined.

S. No.	Name of helicase	Source	Mol. mass (kDa)	Nucleotide cofactors	Polarity	Remarks
1.	ATPase III a	S. cerevisiae	63	ATP > dATP	3′−5′	Stimulated by yeast Pol I.
2.	Rad3 b (XPD)	S. cerevisiae	89	ATP > dATP ≫   CTP	5′−3′	Active at acidic pH; involved in DNA excision repair; homologous to XPD gene.
3.	Rad25 c (SSl2)	S. cerevisiae	95	ATP, dATP	3′−5′	Functions in nucleotide excision repair; homo logous to XPB; required for Pol II transcription.
4.	Srs2d	S. cerevisiae	134	ATP, dATP	3′−5′	Involved in error‐prone repair; negatively modulates recombination.
5.	PIF1 e	S. cerevisiae	97	ATP, dATP	5′−3′	Functions in mitochondrial DNA repair and recombination.
6.	DNA helicase A f	S. cerevisiae	90	ATP, dATP	5′−3′	Copurifies with DNA Pol‐α‐ primase; helicase activity stimulated by the yeast RPA.
7.	DNA helicase B g	S. cerevisiae	127	ATP, dATP > CTPdCTP, UTP	5′−3′	Copurifies with DNA Pol‐δ; stimulated by scRPA; encoded by the yORF61 gene
8.	DNA helicase Ch	S. cerevisiae	32  60	ATP, dATP CTP,dCTP > UTP,GTP > dGTP	5′−3′	Copurifies with DNA Pol δ?
9.	DNA helicase D i	S. cerevisiae	60	ATP,dATP > CTP,dCTP UTP	5′−3′	Copurifies with RF‐C.
10.	ScHel I j	S. cerevisiae	135	ATP, dATP	5′−3′	Stimulated by E. coli SSB.
11.	DNA helicase III k	S. cerevisiae	120	ATP, dATP	5′−3′	Encoded by a gene different from Rad3 and RadH.
12.	Sgs1 l	S. cerevisiae		ATP, dATP	3′−5′	Binds more tightly to a forked DNA substrate than to ss and ds DNA.
13.	Dna2 m	S. pombe	65	ATP, dATP	5′−3′	Involved in DNA replication.
14.	MER3 n	S. cerevisiae	130	ATP	3′−5′	Meiosis‐specific helicase: required for crossing over at time of first meiotic division.
15.	Hmi1p helicase o	S. cerevisiae	80	ATP	nd	Mitochondrial helicase; required for the maintenance of mitochondrial genome.

^a [ 60]; ^b [94]; ^c [95]; ^d [96]; ^e [97]; ^f [98]; ^g [99]; ^{h,  i} [100]; ^j [101]; ^k [102]; ^l [98]; ^m [103]; ⁿ [104]; ^o [105].