TY - JOUR
T1 - The structures of the PII proteins from the cyanobacteria Synechococcus sp. PCC 7942 and Synechocystis sp. PCC 6803
AU - Xu, Yibin
AU - Carr, Paul D.
AU - Clancy, Paula
AU - Garcia-Dominguez, Mario
AU - Forchhammer, Karl
AU - Florencio, Francisco
AU - De Marsac, Nicole Tandeau
AU - Vasudevan, Subhash G.
AU - Ollis, David L.
PY - 2003/12
Y1 - 2003/12
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0347693067&partnerID=8YFLogxK
U2 - 10.1107/S0907444903019589
DO - 10.1107/S0907444903019589
M3 - Article
SN - 0907-4449
VL - 59
SP - 2183
EP - 2190
JO - Acta Crystallographica Section D: Structural Biology
JF - Acta Crystallographica Section D: Structural Biology
IS - 12
ER -