What is the role of RNA polymerase in the process of transcription in eukaryotes?

In eukaryote cells, RNA polymerase III (also called Pol III) transcribes DNA to synthesize ribosomal 5S rRNA, tRNA and other small RNAs. The genes transcribed by RNA Pol III fall in the category of “housekeeping” genes whose expression is required in all cell types and most environmental conditions.

Why do eukaryotes have three RNA polymerases?

Eukaryotic cells contain three distinct nuclear RNA polymerases that transcribe different classes of genes (Table 6.1). Protein-coding genes are transcribed by RNA polymerase II to yield mRNAs; ribosomal RNAs (rRNAs) and transfer RNAs (tRNAs) are transcribed by RNA polymerases I and III.

Can multiple copies of RNA be formed at the same time?

The almost immediate release of the RNA strand from the DNA as it is synthesized means that many RNA copies can be made from the same gene in a relatively short time, the synthesis of additional RNA molecules being started before the first RNA is completed (Figure 6-9).

Why would a cell make an mRNA transcript from a gene?

The instructions in a gene (written in the language of DNA nucleotides) are transcribed into a portable gene, called an mRNA transcript. These mRNA transcripts escape the nucleus and travel to the ribosomes, where they deliver their protein assembly instructions.

How does RNA polymerase accomplish transcription?

The main enzyme involved in transcription is RNA polymerase, which uses a single-stranded DNA template to synthesize a complementary strand of RNA. Specifically, RNA polymerase builds an RNA strand in the 5′ to 3′ direction, adding each new nucleotide to the 3′ end of the strand.

What happens to RNA polymerase after transcription?

What happens to RNA polymerase II after it has completed transcription of a gene? The enzyme is free to transcribe other genes in the cell. RNA polymerase releases the completed RNA and detaches from the DNA.

What do each of the RNA polymerases do?

All eukaryotes have three different RNA polymerases (RNAPs) which transcribe different types of genes. RNA polymerase I transcribes rRNA genes, RNA polymerase II transcribes mRNA, miRNA, snRNA, and snoRNA genes, and RNA polymerase III transcribes tRNA and 5S rRNA genes.

What do RNA polymerases do?

RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription. For instance, bacteria contain a single type of RNA polymerase, while eukaryotes (multicellular organisms and yeasts) contain three distinct types.

What happens to RNA polymerase 2 after it has completed transcription of a gene?

What happens to RNA polymerase II after it has completed transcription of a gene? The enzyme is free to transcribe other genes in the cell. RNA polymerase moves along the DNA strand in the 3′ to 5′ direction, adding nucleotides to the 3′ end of the RNA chain.

What will happen if double stranded RNA is produced during transcription?

Second, the two RNA molecules if produced simultaneously would be complementary to each other. Hence would form a double stranded RNA. This would prevent RNA from being translated into protein and the exercise of transcription would become a fertile one.

What is the role of RNA polymerase?

RNA polymerase is an enzyme that is responsible for copying a DNA sequence into an RNA sequence, duyring the process of transcription.