2]Genomic footprinting of mitochondrial DNA: I. In organello analysis of protein-mitochondrial DNA interactions in bovine mitochondria

Abstract

In organello footprinting involves the use of dimethyl sulfate (DMS) in a methylation protection assay, first used to analyze protein–nuclear DNA interactions in vivo . DMS is a small molecule that methylates guanine residues at the N-7 position and adenines at the N-3 position, making them sensitive to subsequent cleavage at alkaline pH and elevated temperatures. The ability of DMS to permeate mitochondrial membranes readily allows detection of protein–mtDNA interaction within the organelle. During development of the in organello technique, bovine brain cortex mitochondria is used to monitor protein–mtDNA interactions at several domains within the mitochondrial genome considered important in regulating transcriptional and replicative processes.