2dln: Difference between revisions

[[Image:2dln.jpg|left|200px]]<br /><applet load="2dln" size="350" color="white" frame="true" align="right" spinBox="true"  

The molecular structure of the D-alanine:D-alanine ligase of the ddlB gene of Escherichia coli, co-crystallized with an S,R-methylphosphinate and adenosine triphosphate, was determined by x-ray diffraction to a resolution of 2.3 angstroms. A catalytic mechanism for the ligation of two D-alanine substrates is proposed in which a helix dipole and a hydrogen-bonded triad of tyrosine, serine, and glutamic acid assist binding and deprotonation steps. From sequence comparison, it is proposed that a different triad exists in a recently discovered D-alanine:D-lactate ligase (VanA) present in vancomycin-resistant enterococci. A molecular mechanism for the altered specificity of VanA is suggested.

2DLN is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli] with <scene name='pdbligand=MG:'>MG</scene>, <scene name='pdbligand=ADP:'>ADP</scene> and <scene name='pdbligand=PHY:'>PHY</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/D-alanine--D-alanine_ligase D-alanine--D-alanine ligase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=6.3.2.4 6.3.2.4] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2DLN OCA].  

[[Category: Knox, J R.]]

[[Category: Moews, P C.]]

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