in proteins, certain specific orderings of secondary structure that may have a functional role and include Î²-Î±-Î² helix-turn-helix, leucine zippers, calcium binding EF hands, zinc fingers and longer orderings that take on a structural domain such as the Î²-barrel and the immunoglobulin fold.
Deoxyribonucleic acid (/diËÉksiËraÉªbÉµ.njuËËkleÉª.É¨k ËaesÉªd/ ; ËÃ¦SÉªD) dna is a molecule that carries most of the genetic instructions used in the, development functioning and reproduction of all known living organisms and many. virusesranscription is carried out by a DNA-dependent RNA polymerase that copies the sequence of a DNA strand into RNA. To begin transcribing a gene, the RNA polymerase binds to a sequence of DNA called a promoter and separates the DNA strands.
In order to protect the bacterial genomic DNA from its own restriction enzymes, bacterial cells employ a system, wherein methyl transferases methylate certain bases on the DNA â¦ sequence, making them unrecognizable to the restriction enzymes. Each restriction enzyme has a methylase associated with it on the chromosome. This methylase puts methyl groups on the host DNA, and the restriction enzyme doesn't recognize its recognition sequence when it is so methlyated. The host DNA is thus protected from the actions of its own restriction enzyme.