In conversion of DNA to RNA, enzyme required are: (PGI June 2008)
Ans. C (RNA polymerase) RNA polymerase Q is required for RNA synthesis from DNA.DNA polymerase Q required for DNA synthesis and replication.DNA ligase Q used to seal the nick produced by restriction endonuclease.Lippincott Biochemistry 4th/419.422-24In bacteria. one species of RNA polymerase synthesizes all of the RNA except for the short RNA primers needed for DNA replication.!ranscription by RNA polymerase involves a core enzyme and several auxiliary proteins.Core enzyme Q: Four of the enzyme's peptide subunits, 2a, 1b, and 1b' are responsible forthe 5'?3' RNA polymerase activity and are referred to as the core enzyme.Holoenzyme Q The s subunit ("sigma factor*') enables RNA polymerase to recognize promoter regions on the DNA. The a subunit plus the core enzyme make up the holoenzyme.There are three distinct classes Q of RNA polymerase in the nucleus of eukars'otic cells.RNA polymerase 1Q: This enzyme synthesizes the precursor of the 28S, 18S, and 5.8S r-RNA in the nucleolus.RNA polymerase II: This enzyme synthesizes the precursors of m- RNA that are subsequently translated to produce protein. Polymerase II also synthesizes certain small nuclear RNAs, snRNARNA polymerase III: This enzyme produces the small RNA, including tRNA, 5S ribosomal RNA and some snRNA.Also Remember:Materials required for Protein SynthesisAmino acids QDNA & 3 RNAs (m -RNA, t-RNA, r-RNA)Polyribosomes (polysomes) QEnzymes: Aminoacyl-t-RNA synthetase, peptidyl transferaseFactorsIn itia tion facorszelF-1, elF-2, elF-3, elF-4A, elF- 4B, elF-4G, elF-4E, elf-5QElongation factors-EFI & EF2QRelease factors R1 & R2Coenzymes & cofactors; FH4 Mg2+Energy ATP, GTP Q
DNA Polymerase
DNA Ligase
RNA polymerase
Primase
Immunology