  The question of whether DNA conducts electric charges is intriguing to
physicists and biologists alike. The suggestion that electron
transfer/transport in DNA might be biologically important has triggered a
series of experimental and theoretical investigations. Here, we review recent
theoretical progress by concentrating on quantum-chemical, molecular
dynamics-based approaches to short DNA strands and physics-motivated
tight-binding transport studies of long or even complete DNA sequences. In both
cases, we observe small, but significant differences between specific DNA
sequences such as periodic repetitions and aperiodic sequences of AT bases,
lambda-DNA, centromeric DNA, promoter sequences as well as random-ATGC DNA.
