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See detailCrystallographic mapping of β-lactams bound to a D-alanyl-D-alanine peptidase target enzyme
Kelly, Judith A.; Knox, James R.; Zhao, Haiching C. et al

in Journal of Molecular Biology (1989), 209(2), 281-295

X-ray crystallography has been used to examine the binding of three members of the beta-lactam family of antibiotics to the D-alanyl-D-alanine peptidase from Streptomyces R61, a target of penicillins ... [more ▼]

X-ray crystallography has been used to examine the binding of three members of the beta-lactam family of antibiotics to the D-alanyl-D-alanine peptidase from Streptomyces R61, a target of penicillins. Cephalosporin C, the monobactam analog of penicillin G and (2,3)-alpha-methylene benzylpenicillin have been mapped at 2.3 A resolution in the form of acyl-enzyme complexes bound to serine 62. On the basis of the positions of these inhibitors, the binding of a tripeptide substrate for the enzyme, L-lysyl-D-alanyl-D-alanine, has been modeled in the active site. The binding of both inhibitors and substrate is facilitated by hydrogen-bonding interactions with a conserved beta-strand (297-303), which is antiparallel to the beta-lactam's acylamide linkage or the substrate's peptide bond. The active site is similar to that in beta-lactamases. [less ▲]

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See detail2.8-Å Structure of penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 and complexes with β-lactams
Kelly, Judith A; Knox, James R; Moews, Paul C et al

in Journal of Biological Chemistry (1985), 260(10), 6449-6458

The crystallographic structure of the penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 has been solved to 2.8-A resolution. The 38,000-dalton serine peptidase has two ... [more ▼]

The crystallographic structure of the penicillin-sensitive D-alanyl carboxypeptidase-transpeptidase from Streptomyces R61 has been solved to 2.8-A resolution. The 38,000-dalton serine peptidase has two regions of secondary structure, an alpha/beta cluster, and a region which contains five helical segments. The beta sheet is composed of five beta strands. The tertiary structure has no homology with the classic serine proteases or with the zinc carboxypeptidases. The binding at a common site of three types of beta-lactam (a penicillin, a cephalosporin, a monocyclic beta-lactam) and a desazacyclobutanone has been observed in Fourier difference maps. The binding site sequence is Val-Gly-Ser-Val-Thr-Lys. The beta-lactam ring lies near the enzyme's catalytic serine at position 37, and the C3 substituent of a cephalosporin falls near lysine 40. [less ▲]

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See detailPenicillin target enzyme and the antibiotic binding site
Kelly, Judith A.; Moews, Paul C.; Knox, James R. et al

in Science (1982), 218(4571), 479-481

The three-dimensional structure of a penicillin-sensitive D-alanyl-carboxypeptidase-transpeptidase has been determined by x-ray crystallography to a resolution of 2.8 angstroms. The site of binding of the ... [more ▼]

The three-dimensional structure of a penicillin-sensitive D-alanyl-carboxypeptidase-transpeptidase has been determined by x-ray crystallography to a resolution of 2.8 angstroms. The site of binding of the beta-lactam antibiotics penicillin and cephalosporin has been located. These findings constitute direct observation of the interaction of beta-lactams with a transpeptidase enzyme and establish the feasibility of defining the molecular stereochemistry of this interaction for purposes of drug design. [less ▲]

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See detailCrystallographic data for a penicillin receptor : exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61
Knox, James R.; DeLucia, Mary L.; Murthy, N. S. et al

in Journal of Molecular Biology (1979), 127(2), 217-218

A pencillin-sensitive enzyme, the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61, has been crystallized from polyethylene glycol (Mr = 6000 to 7500) solution at pH 7•6. X-ray ... [more ▼]

A pencillin-sensitive enzyme, the exocellular DD-carboxypeptidase-transpeptidase from Streptomyces R61, has been crystallized from polyethylene glycol (Mr = 6000 to 7500) solution at pH 7•6. X-ray examination of the orthorhombic crystals shows the space group is P212121, with unit cell dimensions a = 51•1 Å, B = 67•4 Å, and C = 102•9 Å. With four molecules of molecular weight 38,000, the Å3/dalton ratio for the cell is 2•33. The crystals are stable to irradiation for 75 hours and are suitable for structure analysis to at least 2•4 Å resolution. The radius of gyration of the molecule in solution at pH 6.8 is 20.8 Å. [less ▲]

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