1ion: Difference between revisions

[[Image:1ion.gif|left|200px]]<br /><applet load="1ion" size="350" color="white" frame="true" align="right" spinBox="true"  

BACKGROUND: In Escherichia coli, the cell division site is determined by the cooperative activity of min operon products MinC, MinD, and MinE. MinC is a nonspecific inhibitor of the septum protein FtsZ, and MinE is the supressor of MinC. MinD plays a multifunctional role. It is a membrane-associated ATPase and is a septum site-determining factor through the activation and regulation of MinC and MinE. MinD is also known to undergo a rapid pole-to-pole oscillation movement in vivo as observed by fluorescent microscopy. RESULTS: The three-dimensional structure of the MinD-2 from Pyrococcus horikoshii OT3 (PH0612) has been determined at 2.3 A resolution by X-ray crystallography using the Se-Met MAD method. The molecule consists of a beta sheet with 7 parallel and 1 antiparallel strands and 11 peripheral alpha helices. It contains the classical mononucleotide binding loop with bound ADP and magnesium ion, which is consistent with the suggested ATPase activity. CONCLUSIONS: Structure analysis shows that MinD is most similar to nitrogenase iron protein, which is a member of the P loop-containing nucleotide triphosphate hydrolase superfamily of proteins. Unlike nitrogenase or other member proteins that normally work as a dimer, MinD was present as a monomer in the crystal. Both the 31P NMR and Malachite Green method exhibited relatively low levels of ATPase activity. These facts suggest that MinD may work as a molecular switch in the multiprotein complex in bacterial cell division.

1ION is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Pyrococcus_horikoshii Pyrococcus horikoshii] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=ADP:'>ADP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ION OCA].  

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