The pathogenic role of point mutations affecting the translational initiation codon of mitochondrial genes

The mutation T3308C results in a Met --> Thr change at the highly conserved amino acid position 1 of the mtDNA ND1 gene (M1T). To study its potential pathogenic effect we have carried out a combination of mitochondrial protei n synthesis and Northern and Western analyses. Our data demonstrate that M1 T mutation does not affect the efficiency of the synthesis of the ND1 polyp eptide and suggest that any codon specifying methionine located close to th e 5' end of mitochondrial mRNAs may be used as translational initiator. (C) 2000 Academic Press.