Table 1.

DNA sequence elements involved in the regulated expression of essential factors for mtDNA metabolism in Drosophila

Gene	DNA sequence elements
	DRE	NRG	EWG
pol γ-α	−	−	+
pol γ-β	+	+	−
mtSSB	+	+	−
mtDNA helicase	+	−	−
mtRNA pol	−	+	−
TFAM	+	+	−
mtTFB1	+	−	−
mtTFB2	+	−	−
mtTTF	+	−	−

The proximal promoter (2 Kb) and 3′-upstream gene regions of several genes encoding essential factors for Drosophila mtDNA metabolism have been analyzed in silico, to search for potential binding sites for DREF, NRG and EWG. The functional role of all DREF binding sites except that in the gene for mtTFB1 has been demonstrated by EMSA and cell transfection analyses. [14 (mtSSB), 65 (pol γ-β), 66 (Tfam) and unpublished data from our laboratories].