1qy7
The structure of the PII protein from the cyanobacteria Synechococcus sp. PCC 7942
OverviewOverview
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.
About this StructureAbout this Structure
1QY7 is a Single protein structure of sequence from Synechococcus sp.. Full crystallographic information is available from OCA.
ReferenceReference
The structures of the PII proteins from the cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803., Xu Y, Carr PD, Clancy P, Garcia-Dominguez M, Forchhammer K, Florencio F, Vasudevan SG, Tandeau de Marsac N, Ollis DL, Acta Crystallogr D Biol Crystallogr. 2003 Dec;59(Pt 12):2183-90. Epub 2003, Nov 27. PMID:14646076 Page seeded by OCA on Sat May 3 06:50:47 2008