Question

In: Biology

what is the function of the sigma subunit (factor) of E.coli RNA polymerase in transcription.

what is the function of the sigma subunit (factor) of E.coli RNA polymerase in transcription.

Solutions

Expert Solution

DNA dependent RNA polymerase is the main enzyme involved in gene expression and regulation.A functional RNA polymerase has a core composition of 2 alpha subunit 1 beta 1 beta' and one Omega subunits which along with the Sigma factor forms the RNA polymerase holoenzyme.These all , together are involved in transcription initiation, elongation and termination. Core enzyme is proficient enough to carry out elongation but cannot initiate transcription from promoter on its own. Sigma factor comes into play here,its forms a holoenzyme which recognises and initiates transcription. Sigma factor binds to -35 and -10 consensus promoter elements.At later stages Sigma factor is also involved in abortive RNA synthesis and promoter escape. It is homlogous to eukaryotic transcription factor TFIIB. Number of Sigma factor varies between bacterial species. There are 7 Sigma factors in case of e coli. Structurally they have four main conserved domains.


Related Solutions

TRANSCRIPTION: What does RNA polymerase do in transcription? What is the end product of transcription?
TRANSCRIPTION: What does RNA polymerase do in transcription? What is the end product of transcription?
1. If a mutant sigma factor binds very tightly to RNA polymerase, how might that affect...
1. If a mutant sigma factor binds very tightly to RNA polymerase, how might that affect transcription? It would inhibit the initiation phase of transcription It would inhibit the transition between initiation and elongation. It would inhibit the rate of elongation. It would enhance termination. 2. In bacteria, what type of interaction causes an mRNA to bind to the small ribosomal subunit? The mRNA has a 5’ cap that is recognized by cap proteins that cause it to bind to...
Describe the start of transcription in bacteria and the function of the sigma factor. Give detailed...
Describe the start of transcription in bacteria and the function of the sigma factor. Give detailed answer.
During transcription, RNA polymerase adds new nucleotides
  During transcription, RNA polymerase adds new nucleotides at the carboxy-terminal of the elongating chain at the amino-terminal of the elongating chain at the 3` end of the elongating chain at the 5` end of the elongating chain at both 5` and 3` ends of the elongating chain   Different cells of an organism can produce different types of proteins because They have different genes in different cells Same genes are present in all cells Differential expression of genes in...
The enzyme required for transcription is * RNA polymerase Restriction enzymes Splicesome DNA polymerase
The enzyme required for transcription is * RNA polymerase Restriction enzymes Splicesome DNA polymerase
6. Compare the structure and function of a typical DNA polymerase and a typical RNA polymerase.
6.       Compare the structure and function of a typical DNA polymerase and a typical RNA polymerase.7.       What are the post-transcriptional modifications that the pre-mRNA is subjected to in eukaryotes? Explain by giving the role(s) of each modification.8.       Highlight the general characteristics of a mature mRNA in comparison with rRNA or tRNA
Using DNase footprinting, show that the sigma subunit of prokaryotic RNA Pol binds to nucleotides from...
Using DNase footprinting, show that the sigma subunit of prokaryotic RNA Pol binds to nucleotides from -35 to -10 in the promoter region. a. Outline your experiment and draw and label the data. Explain how your data support this conclusion.    b. Show and label the data for a similar experiment done using DMS footprinting rather than DNase foot printing. Explain how your data support this conclusion.  You do NOT have to write out the experiment again.
Ch 13: Eukaryotic Transcription Worksheet This type of RNA Polymerase is responsible for synthesis of tRNA...
Ch 13: Eukaryotic Transcription Worksheet This type of RNA Polymerase is responsible for synthesis of tRNA _________ This type of RNA Polymerase is responsible for synthesis of mRNA _________ This type of RNA Polymerase is responsible for synthesis of rRNA _________ This “element” decreases the rate of transcription _____________ This “element” increases the rate of transcription _____________ The locations of these elements maybe found _______________________________. This protein is required for RNAP II, it cannot bind without it ____________ These protein...
"RNA polymerase II activity depends on both cis-regulatory elements and trans-acting factor A) What is the...
"RNA polymerase II activity depends on both cis-regulatory elements and trans-acting factor A) What is the main difference between cis-regulatory elements and trans-acting factors? (Hint: which of the two are DNA    sequences, and which one are proteins?)    B) Name and briefly describe the three cis-regulatory elements we have studied in eukaryotes" University-level genetics course, please keep answer as simple and to the point as possible (preferably in bulleted list)... Thank you!
Describe the initiation, elongation and termination phases of transcription. Include the following terms: RNA polymerase, promoter...
Describe the initiation, elongation and termination phases of transcription. Include the following terms: RNA polymerase, promoter DNA sequence, DNA template strand, terminator DNA sequence.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT