The reaction of oxygen with protocatechuate 3,4-dioxygenase from Pseudomonas putida. Characterization of a new oxygenated intermediate.

Rapid Thermostabilization of Bacillus thuringiensis Serovar Konkukian 97–27 Dehydroshikimate Dehydratase through a Structure-Based Enzyme Design and Whole Cell Activity Assay

“…In this case, it is likely that the rate limiting step in β-CMA production occurs after DHB biosynthesis. P. putida PcaG/H is well-known to have properties which limit its utility in a biosynthetic scaffold, including substantial product inhibition and a sensitivity of the biocatalyst to oxygen . Our observations are consistent with PcaG/H acting as the likely rate limiting step in β-CMA formation as well, although little is known about export of this molecule from an E. coli heterologous host.…”

The 1.8 Å crystal structure of catechol 1,2-dioxygenase reveals a novel hydrophobic helical zipper as a subunit linker

“…1,2-CTDs are homodimers whereas 3,4-PCDs are heterodimers that pack together to form higher order oligomers. Depending on the source from which they are purified, 3,4-PCDs have been found to contain two [34], four [16], six [35], or 12 protomers [9,36] in the holoenzyme. Pp 3,4-PCD is a dodecamer in which the β subunits of each protomer assemble into a core sphere, with the α subunits projecting outwards.…”

“…ADP1 (Ac 3,4-PCD; MWV, unpublished observations) [9,10]. An abundance of biochemical and spectroscopic data has been collected from several different sources -P. putida [11][12][13][14][15], Burkholderia cepacia [16,17], and Brevibacterium fuscum [14,[18][19][20]. The ferric ion is ligated by two histidine residues, two tyrosine residues, and a hydroxyl ion in trigonal-bipyramidal geometry.…”

Enzymatic cleavage of aromatic rings: mechanistic aspects of the catechol dioxygenases and later enzymes of bacterial oxidative cleavage pathways

“…89 Bull et al have observed two intermediates in the reaction of protocatechuic acid, O 2 and 3,4-PCD from Pseudomonas putida using stopped flow kinetic analysis. 90 They are denoted ESO 2 and ESO 2 * in Scheme 24 and are characterised by their different UV spectra. 90 The formation of ESO 2 , as a function of O 2 concentration, shifts the Tyr-Fe  charge transfer band at 460 nm of the E • S complex to 400 nm, and reduces the catecholate-Fe  charge transfer band at 700 nm.…”

“…90 They are denoted ESO 2 and ESO 2 * in Scheme 24 and are characterised by their different UV spectra. 90 The formation of ESO 2 , as a function of O 2 concentration, shifts the Tyr-Fe  charge transfer band at 460 nm of the E • S complex to 400 nm, and reduces the catecholate-Fe  charge transfer band at 700 nm. Using the slow substrate 3,4-dihydroxyphenyl propionate (3,4-DHP) a stabilised ESO 2 * intermediate with a distinct peak at 540 nm was observed.…”