The structures of the PII proteins from the cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803
Xu, Yibin, Carr, Paul D., Clancy, Paula, Garcia-Dominguez, Mario, Forchhammer, Karl, Florencio, Francisco, Tandeau de Marsac, Nicole, Vasudevan, Subhash G., and Ollis, David L. (2003) The structures of the PII proteins from the cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803. Acta Crystallographica. Section D: Biological crystallography, 59 (12). pp. 2183-2190.
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The PII proteins from the cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803 have been crystallized and high-resolution structures have been obtained using X-ray crystallography. The core of these new structures is similar to that of the PII proteins from Escherichia coli, although the structures of the T- and C-loops differ. The T-loop of the Synechococcus protein is ordered, but appears to be stabilized by crystal contacts. The same loop in the Synechocystis protein is disordered. The C-terminus of the Synechocystis protein is stabilized by hydrogen bonding to the same region of a crystallographically related molecule. The same terminus in the Synechococcus protein is stabilized by coordination with a metal ion. These observations are consistent with the idea that both the T-loop and the C-terminus of PII proteins are flexible in solution and that this flexibility may be important for receptor recognition. Sequence comparisons are used to identify regions of the sequence unique to the cyanobacteria.
|Item Type:||Article (Refereed Research - C1)|
|Keywords:||crystallography; E. coli; molecular structure; nitrogen; PII proteins; signal transduction|
|Date Deposited:||16 Dec 2009 01:50|
|FoR Codes:||06 BIOLOGICAL SCIENCES > 0601 Biochemistry and Cell Biology > 060107 Enzymes @ 100%|
|SEO Codes:||97 EXPANDING KNOWLEDGE > 970106 Expanding Knowledge in the Biological Sciences @ 100%|
|Citation Count from Web of Science||