2pan

Thiamine diphosphate (ThDP), a derivative of vitamin B1, is an enzymatic, cofactor whose special chemical properties allow it to play critical, mechanistic roles in a number of essential metabolic enzymes. It has been, assumed that all ThDP-dependent enzymes exploit a polar interaction, between a strictly conserved glutamate and the N1' of the ThDP moiety. The, crystal structure of glyoxylate carboligase challenges this paradigm by, revealing that valine replaces the conserved glutamate. Through kinetic, spectroscopic and site-directed mutagenesis studies, we show that although, this extreme change lowers the rate of the initial step of the enzymatic, reaction, it ensures efficient progress through subsequent steps., Glyoxylate carboligase thus provides a unique illustration of the fine, tuning between catalytic stages imposed during evolution on enzymes, catalyzing multistep processes.

2PAN 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=FAD:'>FAD</scene>, <scene name='pdbligand=TDP:'>TDP</scene>, <scene name='pdbligand=DTT:'>DTT</scene> and <scene name='pdbligand=1PE:'>1PE</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Tartronate-semialdehyde_synthase Tartronate-semialdehyde synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.1.47 4.1.1.47] Known structural/functional Sites: <scene name='pdbsite=AC1:Mg Binding Site For Residue A 851'>AC1</scene>, <scene name='pdbsite=AC2:Mg Binding Site For Residue B 851'>AC2</scene>, <scene name='pdbsite=AC3:Mg Binding Site For Residue C 851'>AC3</scene>, <scene name='pdbsite=AC4:Mg Binding Site For Residue D 851'>AC4</scene>, <scene name='pdbsite=AC5:Mg Binding Site For Residue E 851'>AC5</scene>, <scene name='pdbsite=AC6:Mg Binding Site For Residue F 851'>AC6</scene>, <scene name='pdbsite=AC7:Mg Binding Site For Residue A 1501'>AC7</scene>, <scene name='pdbsite=AC8:Mg Binding Site For Residue B 1501'>AC8</scene>, <scene name='pdbsite=AC9:Mg Binding Site For Residue E 1501'>AC9</scene>, <scene name='pdbsite=BC1:Mg Binding Site For Residue F 1501'>BC1</scene>, <scene name='pdbsite=BC2:Fad Binding Site For Residue A 701'>BC2</scene>, <scene name='pdbsite=BC3:Tdp Binding Site For Residue A 801'>BC3</scene>, <scene name='pdbsite=BC4:Dtt Binding Site For Residue A 901'>BC4</scene>, <scene name='pdbsite=BC5:Fad Binding Site For Residue B 701'>BC5</scene>, <scene name='pdbsite=BC6:Tdp Binding Site For Residue B 801'>BC6</scene>, <scene name='pdbsite=BC7:Dtt Binding Site For Residue B 901'>BC7</scene>, <scene name='pdbsite=BC8:Fad Binding Site For Residue C 701'>BC8</scene>, <scene name='pdbsite=BC9:Tdp Binding Site For Residue C 801'>BC9</scene>, <scene name='pdbsite=CC1:Dtt Binding Site For Residue C 901'>CC1</scene>, <scene name='pdbsite=CC2:Fad Binding Site For Residue D 701'>CC2</scene>, <scene name='pdbsite=CC3:Tdp Binding Site For Residue D 801'>CC3</scene>, <scene name='pdbsite=CC4:Dtt Binding Site For Residue D 901'>CC4</scene>, <scene name='pdbsite=CC5:Fad Binding Site For Residue E 701'>CC5</scene>, <scene name='pdbsite=CC6:Tdp Binding Site For Residue E 801'>CC6</scene>, <scene name='pdbsite=CC7:Dtt Binding Site For Residue E 901'>CC7</scene>, <scene name='pdbsite=CC8:Fad Binding Site For Residue F 701'>CC8</scene>, <scene name='pdbsite=CC9:Tdp Binding Site For Residue F 801'>CC9</scene>, <scene name='pdbsite=DC1:Dtt Binding Site For Residue F 901'>DC1</scene> and <scene name='pdbsite=DC2:1pe Binding Site For Residue A 951'>DC2</scene>. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PAN OCA].

[[Category: Chipman, D.M.]]

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