Proteins are manufactured by ribosomes, not by DNA itself.
http://en.wikipedia.org/wiki/Ribosome
What you said is like saying "software is very good at welding auto parts", when in fact, it is industrial robots that can weld, but a paper printout of the control code would not be capable of welding!
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Although DNA cannot be used for biomanufacturing in the way you describe, if you want a different but still interesting example of DNA being used for mechanical purposes, you could look at DNA origami:
DNA origami takes advantage of DNA's ability to self-assemble fairly predictably into 3D shapes based on the designer specifying 1D sequences of letters, which bind to each other with certain propensities.