1jw0: Difference between revisions

[[Image:1jw0.gif|left|200px]]<br /><applet load="1jw0" size="350" color="white" frame="true" align="right" spinBox="true"  

BACKGROUND: Semisynthetic cephalosporins are primarily synthesized from 7-aminocephalosporanic acid (7-ACA), which is obtained by environmentally toxic chemical deacylation of cephalosporin C (CPC). Thus, the enzymatic conversion of CPC to 7-ACA by cephalosporin acylase (CA) would be of great interest. However, CAs use glutaryl-7-ACA (GL-7-ACA) as a primary substrate and the enzyme has low turnover rates for CPC. RESULTS: The binary complex structures of CA with GL-7-ACA and glutarate (the side-chain of GL-7-ACA) show extensive interactions between the glutaryl moiety of GL-7-ACA and the seven residues that form the side-chain pocket. These interactions explain why the D-alpha-aminoadipyl side-chain of CPC yields a poorer substrate than GL-7-ACA. CONCLUSIONS: This understanding of the nature of substrate specificity may be useful in the design of an enzyme with an improved performance for the conversion of CPC to 7-ACA. Additionally, the catalytic mechanism of the deacylation reaction was revealed by the ligand bound structures.

1JW0 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Brevundimonas_diminuta Brevundimonas diminuta] with <scene name='pdbligand=GUA:'>GUA</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1JW0 OCA].  

[[Category: Hol, W G.J.]]

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