7.02 Blast Tutorial

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Blast Tutorial

Part III: 3-D Structure of Ara C Protein


	BLAST Tutorial


	Using the BLAST Tutorial

	Introduction to the Science

	Part I: DNA Sequencing

	Part II: Using BLAST

	Part III: 3-D Structure of Ara C Protein

We used one of the hits to the PDB database to obtain the coordinates of the three-dimensional structure of the Ara C protein, solved by Soissen et al. (1997).

This is the ribbon representation of the arabinose-binding and dimerization domain of the E. coli Ara C protein. Shown is the homodimer that is formed by the association of the two monomers in the presence of arabinose. This dimer binds DNA in a way that stimulates transcription of the ara BAD operon. In the absence of arabinose, AraC forms a different type of dimer that inhibits transcription.

You are now finished with the 7.02 BLAST Tutorial! (Don't forget to check that you answered all the questions on the accompanying BLAST worksheet before you exit!)

REFERENCE: Soisson, S.M., MacDougall - Schackleton, B., Schleif, R., Wolberger, C. (1977). Structural Basis for Ligand-Regulated Oligomerization of Ara C. Science 276:421-425.