RNA Transcription and Sigma Factor

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
Posts: 1
Joined: Thu Oct 13, 2011 9:15 pm

RNA Transcription and Sigma Factor

Post by vashp2029 » Thu Oct 13, 2011 9:22 pm

Hey everyone! I'm new here! I'm working on a study guide for a molecular biology exam and I'll have tons of questions I'm sure but here's the first one.

What sequences does a sigma factor recognize?

I want to say it uses the TATA box in Eukaryots so it recognizes TATA and similar sequences obviously. Is that correct? Also, what sequences are recognized in prokaryotes?

Posts: 115
Joined: Sat Sep 10, 2011 12:58 am

Post by aptitude » Thu Oct 13, 2011 11:01 pm

From Wikipedia for "sigma factor":

Sigma factors have four main regions that are generally conserved:
N-terminus --------------------- C-terminus
1.1 2 3 4
The regions are further subdivided (e.g. 2 includes 2.1, 2.2, etc.)
Region 1.1 is found only in "primary sigma factors" (RpoD, RpoS in E.coli). It is involved in ensuring the sigma factor will only bind the promoter when it is complexed with the RNA polymerase.
Region 2.4 recognizes and binds to the Pribnow box.
Region 4.2 recognizes and binds to the -35 promoter site.

Post Reply

Who is online

Users browsing this forum: No registered users and 10 guests