Functions of Taq DNA Polymerase in PCR Reaction

Restriction Enzymes or Restriction Endonucleases or Molecular Scissors found in bacteria to provide defense mechanism against invading viruses by degrading viral DNA without affecting bacterial DNA, Each bacterium has its own unique restriction enzyme and each enzyme recognize only one type of sequence so DNA sequence that recognize by restriction enzymes called palindromes which are sequences read same on two strands in opposite directions, Mechanisms of restriction enzymes start by scan DNA then bind to DNA to recognize specific sequence after that cut each sugar-phosphate backbone of DNA by hydrolyze phosphodiester bonds, Restriction Enzymes have four types: (Type-1: Cleave DNA at random length from recognition sites) (Type-2: Cleave DNA in close of recognition site so it useful for gene analysis and cloning) (Type-3: Cleave outside recognition sequence so it require two recognition sequence in opposite directions within same DNA) (Type-4: Cleave only modified DNA in approximate 30 base pair away from sites), Sticky 5’ Overhang, Sticky 3’ Overhang, Blunt Ends without Overhang, Sticky ends Restriction Enzymes called also Cohesive ends Restriction Enzymes because they are useful for DNA manipulation and can be converted to blunt ends with nuclease or polymerase while Blunt ends Restriction Enzymes useful for certain types of DNA cloning experiments and can be converted to sticky ends by ligating to synthetic adaptors, For Restriction Enzymes Mapping must digest DNA with restriction enzymes then resolve digested fragments by gel electrophoresis and the resulted bands on gel refer to., number of restriction sites while size of bands refer to distance between restriction sites, Restriction enzymes used in gene characterization by RFLP markers and gene mapping such as restriction maps and gene manipulation such as gene cloning and protein expression experiments (Watch Related Video in #geneticteacher) #geneticteacher