Ribonucleic acid polymerase structure

Goff CG (1974) Chemical structures of a modification of X iQ Escherichia coli ribonucleic acid polymerase a polypeptides induced by bacteriophage T4 infection. J Biol Chem 249 6181-6190... 

Schwartz, L. B., and Roeder, R. G., 1975, Purification and subunit structure of deoxyribonucleic acid-dependent ribonucleic acid polymerase II from the mouse plasma cytoma, MOPC315, J. Biol. Chem. 250 3221-3228. 

Rickets, 482,483,575,576, 582,583, 584 Rislt ratio, 908, 965-%6,968 RMR, see Resting iretabolic rate RNA (ribonucleic acid), 12 cellular function, 32 chetnical structure, 13 structure, 937 synthesis, 13,16 RNA polymerase, 33-35 RNasas, 122 Rods, 561,563-564 rRNA (ribosomal RNA), 34 Rubidium, 703... 

The information which specifies the amino-acid sequence of a protein is stored in the nucleotide sequence of the double helix of deoxyribonucleic acid (DNA). The transcription of sections of this information into ribonucleic acid (RNA) is catalysed by RNA polymerases. These enzymes not only control the synthesis of RNA but also recognize stop and start signals on the DNA. The start signals are complex and may be blocked by repressor molecules which inhibit the transcription process. Once synthesized, the (messenger) RNA is processed and exported to ribosomes where its nucleotide sequence is translated into protein. Triplets of three nucleotides (codons) in the messenger RNA each specify (encode) one amino acid. The linear sequence of nucleotides in the messenger RNA thus specifies the sequence of amino acids in the protein whose primary structure will therefore correspond directly to the sequence of nucleotides in the DNA. 

For all forms of DNA, hydrogen bonding between the two spiral chains stabilizes the double helix. Replication of DNA occurs when the hydrogen bonds are broken, and the two strands are separated. These form the templates that are used to make identical copies, via enzymes called DNA polymerases. In fact, the second strand of the double helix is complementary to the first, it contains no extra information but is involved in replication. Ribonucleic acid (RNA) is also found in cells. It has a similar structure to DNA, but the sugar is instead D-ribose and uracil bases replace thymine bases. RNA is important in the synthesis of proteins. It is produced from DNA templates via the process of transcription. Further details of protein biochemistry can be found elsewhere (e.g. Voet and Voet, 1995). Here we simply emphasize that life itself is created from that special class of soft material called polymers. 

Ribonucleic acid (RNA) is the other major nucleic acid besides DNA, but unlike DNA, it is single stranded. It contains ribose instead of deoxyribose as its sugar—phosphate backbone and uracil (U) instead of thymine (T) in its pyrimidine bases (Nilsson et al., 2015). Like DNA, BJSIA can be assembled from nucleotides using DNA sequence as a template and RNA polymerase. The structure of an RNA molecule is also determined by its... 

In like manner, ribosomal ribonucleic acid (rRNA) and transfer ribonucleic acid (tRNA) are synthesized from their specific genes through the action of DNA-dependent RNA polymerase. And as in the case of mRNA, each of the precursor forms of these nucleotides are also processed until they reach their final forms. The rRNAs and a large variety of ribosomal proteins are assembled to form the ribosome. Ribosomes, the supramolecular structures in which protein synthesis takes place and which functionally resemble multienzyme complexes, are elaborate structures. They are attached, by a binding site on the smaller subribosomal particle, to the endoplasmic reticulum. The tRNAs that are synthesized finally become charged with specific amino acids. 

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