[Geoffrey]

How does DNA polymerase move along a strand of DNA?

[Yggdrasil]

The energy from hydrolysis of the nucleotide triphosphates is coupled to the movement of the polymerase on DNA.  The exact mechanisms underlying the movement are not yet well understood and this question is an area of active research (see the work of Carlos Bustamante at Berkeley or Steven M Block at Stanford (although he works with RNA polymerases, not DNA polymerases)).

It has also been shown that HIV reverse transcriptase (a DNA polymerase) and RNA polymerase are capable of diffusing 1-dimensionally along DNA via a sliding mechanism (see Liu S et al. Science 2008, doi:10.1126/science.1163108 and Kabata H et al. Science 1993, doi:10.1126/science.8248804).

[Geoffrey]

Thanks for the reply,

Unfortunately I'm not able to access the papers you linked, but I've found some (possibly related) stuff about 'brownian motors'.  I'm not sure how triphosphates fit into the picture though, it seems to me they would be exhausted pretty quickly.