1m7y: Difference between revisions

[[Image:1m7y.jpg|left|200px]]<br /><applet load="1m7y" size="350" color="white" frame="true" align="right" spinBox="true"  

The 1.6-A crystal structure of the covalent ketimine complex of apple 1-aminocyclopropane-1-carboxylate (ACC) synthase with the potent inhibitor l-aminoethoxyvinylglycine (AVG) is described. ACC synthase catalyzes the committed step in the biosynthesis of ethylene, a plant hormone that is responsible for the initiation of fruit ripening and for regulating many other developmental processes. AVG is widely used in plant physiology studies to inhibit the activity of ACC synthase. The structural assignment is supported by the fact that the complex absorbs maximally at 341 nm. These results are not in accord with the recently reported crystal structure of the tomato ACC synthase AVG complex, which claims that the inhibitor only associates noncovalently. The rate constant for the association of AVG with apple ACC synthase was determined by stopped-flow spectrophotometry (2.1 x 10(5) m(-1) s(-1)) and by the rate of loss of enzyme activity (1.1 x 10(5) m(-1) s(-1)). The dissociation rate constant determined by activity recovery is 2.4 x 10(-6) s(-1). Thus, the calculated K(d) value is 10-20 pm.

1M7Y is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Malus_x_domestica Malus x domestica] with <scene name='pdbligand=PPG:'>PPG</scene> and <scene name='pdbligand=MRD:'>MRD</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/1-aminocyclopropane-1-carboxylate_synthase 1-aminocyclopropane-1-carboxylate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.4.1.14 4.4.1.14] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1M7Y OCA].  

[[Category: Gruetter, M G.]]

[[Category: Kirsch, J F.]]

''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:52:33 2008''