User:Ketan Mathavan/Sandbox 1
From Proteopedia
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| - | + | <Structure load='3SPA' size='250' frame='true' align='right' caption='Human mitochondrial RNA polymerase' scene='Insert optional scene name here' /> | |
| + | One of the [[CBI Molecules]] being studied in the [http://www.umass.edu/cbi/ University of Massachusetts Amherst Chemistry-Biology Interface Program] at UMass Amherst and on display at the [http://www.molecularplayground.org/ Molecular Playground]. | ||
| + | '''Transcription and the human mitochondrial RNA polymerase ''' | ||
| - | + | The central dogma of biology in which genetic information is transferred from DNA to RNA, and subsequently into protein, is fundamental to life. A key player in this process is the DNA-dependent RNA polymerase. RNA polymerase produces RNA in the presence of a DNA template under tight control by the cell. In the Martin lab, our goal is to elucidate the energetics and thermodynamics of this complicated process. As a model, we use T7 bacteriophage RNA polymerase. This single-subunit polymerase can transcribe DNA without assistance from other proteins, making it an ideal model to understand transcription. Likewise, it is representative of all other known RNA polymerases in that it initiates at unique positions along the DNA, undergoes abortive cycling, transitions to a stable elongation complex, and terminates transcription at specific sequences. | |
| - | [['''Bold text'''Image:intactModelLargeText.jpg|frame|Bacterial chemotaxis receptor]] | ||
| - | One of the [[CBI Molecules]] being studied in the [http://www.umass.edu/cbi/ University of Massachusetts Amherst Chemistry-Biology Interface Program] at UMass Amherst and on display at the [http://www.molecularplayground.org/ Molecular Playground]. | ||
| - | + | Initially transcribing complexes are relatively unstable through about the first 8-10 bases of transcription. During this time, short RNA transcripts are made and released in a process known as abortive cycling. Abortive cycling in particular, and promoter-proximal pausing more generally, plays key roles in gene regulation. Thus understanding the mechanism of initial transcription is key to understanding cellular regulation. | |
Revision as of 04:33, 14 December 2011
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One of the CBI Molecules being studied in the University of Massachusetts Amherst Chemistry-Biology Interface Program at UMass Amherst and on display at the Molecular Playground.
Transcription and the human mitochondrial RNA polymerase
The central dogma of biology in which genetic information is transferred from DNA to RNA, and subsequently into protein, is fundamental to life. A key player in this process is the DNA-dependent RNA polymerase. RNA polymerase produces RNA in the presence of a DNA template under tight control by the cell. In the Martin lab, our goal is to elucidate the energetics and thermodynamics of this complicated process. As a model, we use T7 bacteriophage RNA polymerase. This single-subunit polymerase can transcribe DNA without assistance from other proteins, making it an ideal model to understand transcription. Likewise, it is representative of all other known RNA polymerases in that it initiates at unique positions along the DNA, undergoes abortive cycling, transitions to a stable elongation complex, and terminates transcription at specific sequences.
Initially transcribing complexes are relatively unstable through about the first 8-10 bases of transcription. During this time, short RNA transcripts are made and released in a process known as abortive cycling. Abortive cycling in particular, and promoter-proximal pausing more generally, plays key roles in gene regulation. Thus understanding the mechanism of initial transcription is key to understanding cellular regulation.
A bacterial chemotaxis receptor is an unusually long alpha-helical structure. The attractant molecule (the ligand) binds near the top of this picture and sends a signal across the membrane into the cell to control proteins that bind near the bottom. This is a model of the structure of the receptor based on experimental structures of pieces of related proteins.
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Ligand-binding domain
The spinning protein () ) is the ligand binding domain of the aspartate receptor with the aspartate ligand bound (LKT).
Molecular Playground banner: A bacterial chemotaxis receptor protein used by bacteria to "smell" their environment.
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Chemotaxis adaptor protein CheW
CheW is a chemotaxis adaptor protein, and part of the tertiary complex formed by the chemotaxis receptor, histidine kinase protein CheA, and CheW. As an adaptor protein, CheW mediates the interaction between the chemotaxis receptor and CheA, and is necessary for the formation of kinase active complexes. CheW has been found to bind to the P5 domain of CheA through crystallographic studies.
At right, CheW is shown with suppression mutants (blue)that have been measured to decrease receptor binding and chemotaxis (SMJ).
