Difference between revisions of "Part:BBa K352001"

Latest revision as of 00:06, 29 October 2010

CooA from Rhodospirillum rubrum

CooA transcriptional activator makes possible to sense CO and use CO as single energy source for Rhodospirillum rubrum and also it has heme groups.

The structure of the CooA protein has two residues of Tryptophan. Carbon monoxide binding to protein and DNA binding to protein can cause conformational change in the protein structure so tryptophan orientation change in the protein. Intrinsic tryptophan fluorescence experiment shows that any fluorescence intensity change and fluorescence shift resulting from the change of tryptophan. We see a little difference between binding of promoter of oxidized and reduced CO bounded CooA protein. Decrease in the intensity is obtained.

The structure of CooA is given above(by Jmol):

CooA founds under a transcriptional regulators family which resembles the cAMP receptor protein and fumavate nitrate reduction from Escherichia coli. The protein functions upon in sequence-specific DNA binding when CO exists at the environment. CO dependent CooA is at the dimer structure when CO does not exist. CooA, is 28% identical (51% similar) to CRP(cAMP receptor protein) and 18% identical (45% similar) to FNR(fumavate nitrate reduction) of the Escherichia coli.

The strain has 1FT9 ID number from PDB was used for adaptation of the inactive Fe(II) CooA structure. Two monomers of the protein darkened distinctively. These monomers dimerize along the middle C-helices of adjacent effector-binding domains. Identified structure of the protein is not symmetric and one monomer has fused C- and D-helices. However, two F-helices are away from the surface structure and they act on DNA in a sequence-specific manner. The 4/5 loop, the Pro2 and His77 heme Fe(II) ligands are noted.

Sequence and Features