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Research has been conducted on Pseudomonas putida (S)-Mandelate dehydrogenase. The catalytic role of arginine residues Arg 165 and Arg 277 present in these enzymes and the importance of Arg165/Arg277 pair have been investigated and the results are reported.

Research has been conducted on Pseudomonas putida benzoate 1,2-dioxygenase system. The use of the two-component Rieske dioxygenase system in demonstrating the ability of its oxygenase component to leave both metal centers in the oxidized states is described.

Research has been conducted on the ketosteroid isomerase from Pseudomonas putida biotype B. The structural and functional roles of the tyrosine residues' phenyl rings in the active site of P. putida ketosteroid isomerase have been investigated and discussed.

Research has been conducted on the adrenodoxin-type Escherichia coli ferredoxin. The crystal structure of this ferredoxin has been determined via the multiple-wavelength anomalous dispersion method and the results indicate that its structure is similar to the bovine adrenodoxin and Pseudomonas putida putidaredoxin structures.

Research points out that in the putidaredoxin-P450cam redox couple the complex fomation occurs electrostatically whereas in case putidaredoxin-NADH-putidaredoxin reductase, the association is driven by nonelectrostatic interactions as shown by laser flash photolysis technique.

Research has been conducted on the alkyl-isocyanides capable of binding to both ferric and ferrous heme iron in cytochrome P450. The crystallographic and spectrophotometric properties of the isocyanide complexes of Pseudomonas putida cytochrome P450cam and Fusarium oxysporum cytochrome P450nor have been investigated.

Pseudomonas putida and arginine 277 have been studied. The role of arginine 277 in (S)-mandelate dehydrogenase in substrate binding and transition state stabilization was the study focus. Results indicate that R277 has an important role in transition state stabilization via its positive charge and forms a certain hydrogen bond with the substrate and the transition state. Results relative to the stabilization are consistent with a mechanism that involves a carbanion intermediate.

The stereospecificity of 4-oxalocrotonate tautomerase from Pseudomonas putida mt-2 and 5-(carboxymethyl)-2-hydroxymuconate isomerase from Escherichia coli C was determined. The product, 2-oxo-3-(E)-hexenedioate was trapped and processed to (2-2H1)glutaric acid by chemical degradative procedures. It was found that both enzymes ketonize 2-hydroxymuconate stereospecifically to (S)-2-oxo-3-(E)-(5-2H1)hexenedioate.

Several studies are conducted to explain the protein salvation response observed along the reaction coordinate present in the active site of ketosteroid isomerase. The catalytic cycle is shown to have no impact on the electrostatic environment of the active site.

The article explains the X-ray structures and the properties of P450cam, which is obtained from Pseudomonas putida and is crystallized in the absence of substrates. The compound is shown to be capable of dynamically visiting an open conformation without the induction of any ligand.

The various characteristics associated with the proton affinity of the oxyanion hole present in the active site of ketosteroid isomerase are discussed. The strength of the hydrogen bond in the compound is shown to increase with a decrease in the photon affinity.

A point mutant, benzaldehyde lyase (BAL) from Pseudomonas putida A28S which is able to catalyze the decarboxylation of benzoylformate and is inactivated by the benzoylformate analogues methyl benzoylphosphonate (MBP) and benzoylphosphonate (BP), similar to benzoylformate decarboxylase (BFDC) is reported. The findings suggested that an appropriately placed nucleophile facilitated the expulsion of carbon dioxide from the active site in many thiamin diphosphate (ThDP-dependent decarboxylases.

The (Pdr-Pdx) C73S/C85S conjugate was purified and characterized to gain insight into the cytochrome P450cam-dependent monooxygenase system from Pseudomonas putida, putidaredoxin (Pdx) which shuttles electrons between putidaredoxin reductase (Pdr) and P450cam to form transient complexes with both partners. The high specificity of the Pdr-Pdx couple might be attributed to finely tuned interactions at the protein-protein interface resulting in only one strongly preferred docking orientation leading to efficient FAD-to-[2Fe-2S] electron transfer.

A kinetic and thermodynamic analysis of xenobiotic reductase A (XenA) from Pseudomonas putida which is a member of the old-yellow-enzyme family of flavin-containing enzymes and catalyzes the NADH/NADPH-dependent reduction of various substrates, including 8-hydroxycoumarin and 2-cyclohexenone is reported. The result obtained confirmed the link between XenA and other members of the old-yellow-enzyme family and demonstrated several differences in the reactivity of these enzymes.

The identification of a second LOV homologue, PpSB1-LOV present in the common soil bacterium Pseudomonas putida, that exhibited a plant phototropin LOV-like photochemistry and with approximately 66% identical amino acids is reported. The interesting interchange of the C-terminal extensions between the two LOV proteins, (PpSB1-LOV and PpSB2-LOV) which have a pronounce effect on the dark recovery time constants, highlighted a coupling of these protein regions to the chromophore binding pocket.

The different stereochemical mechanisms involved in the two different families of cis,cis-muconate lactonizing enzymes (MLEs) are analyzed to explain the evolution of the various enzymatic activities in the enolase superfamily. The different structural strategies that are used for determining substrate specificity in these enzymes are shown to lead to the observed stereochemical differences.

An isothermal titration calorimetric study of the binding of substrates and inhibitors to different complexes of tartrate dehydrogenase (TDH) from Pseudomonas putida was carried out. The kinetic mechanism of TDH requires nicotinamide adenine dinucleotide (NAD), [K.sup.+] and [Mn.sup.2+] to be bound to the enzyme before D-malate can bind and the binding of NAD and [K.sup.+] is synergistic.