More Recent Comments

Tuesday, August 07, 2007

Theme: Transcription

Transcription is one of the key steps in the flow of information from gene to protein. Transcription is the process by which information in double-stranded DNA is copying into a molecule of RNA.

The postings listed below describe the various steps of transcription and the structure of RNA polymerase.

March 19, 2007
Monday's Molecule #18. The molecule is α-amanitin, an important inhibitor of RNA polymerase.

March 19, 2007
Gene and Transcription Orientation. This article describes the relationship between a gene and its RNA.

March 19, 2007
Transcription. Covers the essentials of transcription: initiation, elongation, termination.

March 20, 2007
Mushrooms for Dinner. How Julia Agrippina disposed of her husband and put her son, Nero, on the throne.

March 20, 2007
Eukaryotic RNA Polymerases. Describes the five different kinds of RNA polymerase in eukaryotic cells.

March 21, 2007
Nobel Laureate: Roger D. Kornberg (Chemistry 2006) "for his studies of the molecular basis of eukaryotic transcription"

March 21, 2007
How RNA Polymerase Works: The Chemical Reaction. This posting explains the chemical reaction of RNA polymerization.

March 22, 2007
How RNA Polymerase Works: The Topology of the Reaction and the Structure of the Enzyme. The structure of RNA polymerases is illustrated using the yeast and E. coli enzymes as examples. How RNA polymerase succeeds in unwinding RNA from it's DNA template is described.

March 25, 2007
RNA Polymerase Genes in the Human Genome. This article was written for Gene Genie. It describes the locations of the human genes for RNA polymerase subunits.

August 7, 2007
Hype and Reality in an Important Transcription Paper. A discussion of a recent paper demonstrating the actions of RNA polymerases in mammalian nuclei.

September 27, 2007
Transcription of the 7SL Gene. How the 7SL gene is transcribed by RNA polymerase III and the significance of internal promoters in creating junk DNA.

February 7, 2008
Junk RNA. Much of the mammalian genome may be transcribed by accident and the resulting RNAs are quicky degraded.

February 7, 2008
Regulation of Transcription. An overview of the main forms of transcriptional regulation.

February 12, 2008
Repression of the lac Operon. This is a description of the binding properties of lac repressor, used as an introduction to DNA binding proteins.

February 12, 2008
Transcription Factors Bind Thousands of Active and Inactive Regions in the Drosophila Blastoderm. Transcription factors bind to thousands of sites on the Drosophila genome. Many of the sites appear to be non-functional.


Anonymous said...

Okay, so how does the system know which side of the DNA to copy to m-RNA?

Larry Moran said...

RNA polymerase binds to the promoter at the 5' end of the gene. The promoter is asymmetrical so binding results in a transcription complex that's pointed in one direction; namely, toward the gene.

Since the DNA stands are anti-parallel, the chemistry of the transcription reaction means that only one of the strands can be copied into RNA as the elongation reaction proceeds.

Thus, the correct strand of DNA is determined by the position of the promoter relative to the DNA that has to be copied.

via gene said...

I didn't get it... why that figure is not the "Central Dogma"? Looks the same to me... (the "original" central dogma). Great blog!
ana claudia

Larry Moran said...

via gene asks,

I didn't get it... why that figure is not the "Central Dogma"? Looks the same to me... (the "original" central dogma).

Read Basic Concepts: The Central Dogma of Molecular Biology to see why that isn't the real Central Dogma of Molecular Bioogy.

Biologist's blog said...

Ah,one might ask why Robert Roeder didnt get the Nobel Prize
for purifying/discovering all 3 RNA polymerases? Kornberg contributed to the understanding of the process of transcription.

Larry Moran said...

RNA polymerase

"RNAP was discovered independently by Charles Loe, Audrey Stevens, and Jerard Hurwitz in 1960.[1] By this time, one half of the 1959 Nobel Prize in Medicine had been awarded to Severo Ochoa for the discovery of what was believed to be RNAP,[2] but instead turned out to be polynucleotide phosphorylase."