Name the enzyme that facilitates opening of DNA helix during transcription.

DNA dependent RNA polymerase somehow also facilitates opening of helix and continues elongation. It uses nucleoside triphosphates as substrate and polymerises in a template depended fashion following the rule of complementarity.DNA helicase  unwind the DNA helix and unzips the the two strands.DNA polymerase  adds complementary deoxyribo nucleotides towards the 3' end of primer.DNA ligase facilitates the joining of DNA strands together by catalyzing the formation of a phosphodiester bond.