DNA 'Sloppier Copier' Surprisingly Efficient: Three Major Puzzles About Famous Enzyme Solved:
"The enzyme known as DNA polymerase V (pol V) comes in when a cell's DNA is reeling from radiation damage or other serious blows. Pol V copies the damaged DNA as best it can – saving the life of the bacterial cell at the cost of adding hundreds of random mutations.
The July 16 Nature study reveals pol V's key attributes: economy of motion and quickness to engage.
The study also solves two other stubborn mysteries about the mechanics of DNA repair: the exact composition of the active form of pol V and the crucial role of a protein filament, known as RecA*, that is always present around DNA repair sites, but was never shown to be directly involved."