Disease relevance of ECs1469

• We report the first bacterial strain lacking KAS III, a fabH mutant constructed in the Gram-positive bacterium Lactococcus lactis subspecies lactis IL1403 [1].
• The deduced amino acid sequence was 48 and 45% identical with the putative KAS III of Porphyra umbilicalis and KAS III of E. coli, respectively [2].

High impact information on ECs1469

• The mutant strain carries an in-frame deletion of the KAS III active site region and was isolated by gene replacement using a medium supplemented with a source of saturated and unsaturated long-chain fatty acids [1].
• Based on the amino acid sequence of tryptic digests of purified spinach KAS III, degenerate polymerase chain reaction (PCR) primers were designed and used to amplify a 612-bp fragment from first-strand cDNA of spinach leaf RNA [2].
• Working with KAS IIIs from Cuphea seeds we obtained kinetic evidence that KAS III catalysis follows a Ping-Pong mechanism and that these enzymes have substrate-binding sites for acetyl-CoA and malonyl-ACP [3].
• Incubations with chloroplasts and direct assay of the individual condensing enzymes showed that all three compounds inhibited the pea FAS condensing enzymes in the order KAS II > KAS I > KAS III [4].
• Finally, alanine scanning revealed the involvement of Arg(150) and Arg(306) in KAS III catalysis [3].

Chemical compound and disease context of ECs1469

• Expression of the functional recombinant perilla KAS III increased the myristate level in E. coli but it exerted no appreciable effect on cell growth [5].

Biological context of ECs1469

• Its deduced amino acid sequence matched the sequences of the tryptic digests obtained from the purified KAS III [2].
• This and other evidence suggests that in E. coli the accumulation of C14:0 may not be a direct effect of the KAS III overexpression, but a general metabolic consequence of the arrest of cell division [6].
• beta-Ketoacyl-ACP synthase III (FabH), an essential enzyme for bacterial viability, catalyzes the initiation of fatty acid elongation by condensing malonyl-ACP with acetyl-CoA [7].
• Comparison to the active site architectures of other thiolase fold enzymes carrying out a decarboxylation step suggests that chalcone synthase and KAS III with Cys-His-Asn triads use another mechanism in which both the histidine and the asparagine interact with the thioester oxo group [8].
• We isolated two KAS III cDNA isoforms (PfKAS3a and PfKAS3b) from a cDNA library specific to Perilla frutescens immature seeds [5].

Anatomical context of ECs1469

• Bacterial KAS III was expressed in a seed- and developmentally specific manner in B. napus in either cytoplasm or plastid [6].

Associations of ECs1469 with chemical compounds

• Its enzymological characteristics were similar to those of two other plant KAS III enzymes except for its inhibition by thiolactomycin [9].

Analytical, diagnostic and therapeutic context of ECs1469

• Dynamic light scattering, size exclusion chromatography, and mass spectrometry results indicated that selenomethionyl KAS III is a noncovalent homodimer [10].
• Crystallization of Escherichia coli beta-ketoacyl-ACP synthase III and the use of a dry flash-cooling technique for data collection [11].

References