1gpd: Difference between revisions

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

An improved electron density map of lobster holo-D-glyceraldehyde-3-phosphate dehydrogenase has been computed to 2.9 A resolution based on two heavy atom isomorphous derivatives. This has been averaged only over the Q molecular 2-fold axis, which is known to be exact in the human holoenzyme. The map showed possible asymmetry between the subunits in which the active centers are closely related across the R axis (that is, between the red and green or between the yellow and blue subunits). A difference map between the electron density of citrate and sulfate-soaked crystals gave further evidence for possible asymmetry. The major differences of electron density between R axis-related subunits appear around the active center and suggest the following interpretations. 1. The conformation of the adenine about the glycosidic bond is the more frequently observed anti with a C-2' endo conformation for the ribose ring in the red and yellow subunits, but is probably syn with a C-3' endo conformation in the green and blue subunits.2. The adenine ribose has its 3'-hydroxyl group hydrogen-bonded to a main chain carbonyl group in the red and yellow subunits but not in the green and blue subunits, as a consequence of the differing ribose conformations. 3. Cysteine-149 is more closely associated with histidine-176 in the green and blue subunits, and appears nearer the nicotinamide in the red and yellow subunits.

1GPD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homarus_americanus Homarus americanus] with <scene name='pdbligand=PO4:'>PO4</scene>, <scene name='pdbligand=ACE:'>ACE</scene> and <scene name='pdbligand=NAD:'>NAD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Glyceraldehyde-3-phosphate_dehydrogenase_(phosphorylating) Glyceraldehyde-3-phosphate dehydrogenase (phosphorylating)], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.2.1.12 1.2.1.12] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GPD OCA].  

[[Category: Ford, G C.]]

[[Category: Olsen, K W.]]

[[Category: Rossmann, M G.]]

[[Category: Sabesan, M N.]]

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