1gk0: Difference between revisions
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==Overview== | ==Overview== | ||
Glutarylamidase is an important enzyme employed in the commercial, production of 7-aminocephalosporanic acid, a starting compound in the, synthesis of cephalosporin antibiotics. 7-aminocephalosporanic acid is, obtained from cephalosporin C, a natural antibiotic, either chemically or, by a two-step enzymatic process utilizing the enzymes D-amino acid oxidase, and glutarylamidase. We have investigated possibilities for redesigning, glutarylamidase for the production of 7-aminocephalosporanic acid from, cephalosporin C in a single enzymatic step. These studies are based on the, structures of glutarylamidase, which we have solved with bound phosphate, and ethylene glycol to 2.5 A resolution and with bound glycerol to 2.4 A., The phosphate binds near the catalytic serine in a way that mimics .. | Glutarylamidase is an important enzyme employed in the commercial, production of 7-aminocephalosporanic acid, a starting compound in the, synthesis of cephalosporin antibiotics. 7-aminocephalosporanic acid is, obtained from cephalosporin C, a natural antibiotic, either chemically or, by a two-step enzymatic process utilizing the enzymes D-amino acid oxidase, and glutarylamidase. We have investigated possibilities for redesigning, glutarylamidase for the production of 7-aminocephalosporanic acid from, cephalosporin C in a single enzymatic step. These studies are based on the, structures of glutarylamidase, which we have solved with bound phosphate, and ethylene glycol to 2.5 A resolution and with bound glycerol to 2.4 A., The phosphate binds near the catalytic serine in a way that mimics the, hemiacetal that develops during catalysis, while the glycerol occupies the, side-chain binding pocket. Our structures show that the enzyme is not only, structurally similar to penicillin G acylase but also employs essentially, the same mechanism in which the alpha-amino group of the catalytic serine, acts as a base. A subtle difference is the presence of two catalytic, dyads, His B23/Glu B455 and His B23/Ser B1, that are not seen in, penicillin G acylase. In contrast to classical serine proteases, the, central histidine of these dyads interacts indirectly with the O(gamma), through a hydrogen bond relay network involving the alpha-amino group of, the serine and a bound water molecule. A plausible model of the, enzyme-substrate complex is proposed that leads to the prediction of, mutants of glutarylamidase that should enable the enzyme to deacylate, cephalosporin C into 7-aminocephalosporanic acid. | ||
==About this Structure== | ==About this Structure== | ||
1GK0 is a | 1GK0 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Pseudomonas_sp. Pseudomonas sp.] with PO4 and EDO as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Penicillin_amidase Penicillin amidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.5.1.11 3.5.1.11] Structure known Active Site: POB. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1GK0 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: x-raz structure]] | [[Category: x-raz structure]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 12:31:07 2007'' | ||
