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Modular Polyketide Synthases (modular + polyketide_synthase)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

Improved Catalytic Activity of a Purified Multienzyme from a Modular Polyketide Synthase after Coexpression with Streptomyces Chaperonins in Escherichia coli.

CHEMBIOCHEM, Issue 18 2008
Lorena Betancor
Folding helpers: Coexpression of Streptomyces coelicolor chaperonins GroEL1, GroEL2 and GroES with an actinomycete-derived polyketide synthase multienzyme in Escherichia coli has beneficial effects on yield, folding and specific activity of the purified enzyme. The results strongly suggest the utility of chaperones derived from polyketide-producing actinomycete bacteria in optimising the recombinant production of PKS proteins in E. coli for detailed studies of structure and function. [source]

Solution structure and proposed domain,domain recognition interface of an acyl carrier protein domain from a modular polyketide synthase

PROTEIN SCIENCE, Issue 10 2007
Viktor Y. Alekseyev
Abstract Polyketides are a medicinally important class of natural products. The architecture of modular polyketide synthases (PKSs), composed of multiple covalently linked domains grouped into modules, provides an attractive framework for engineering novel polyketide-producing assemblies. However, impaired domain,domain interactions can compromise the efficiency of engineered polyketide biosynthesis. To facilitate the study of these domain,domain interactions, we have used nuclear magnetic resonance (NMR) spectroscopy to determine the first solution structure of an acyl carrier protein (ACP) domain from a modular PKS, 6-deoxyerythronolide B synthase (DEBS). The tertiary fold of this 10-kD domain is a three-helical bundle; an additional short helix in the second loop also contributes to the core helical packing. Superposition of residues 14,94 of the ensemble on the mean structure yields an average atomic RMSD of 0.64 ± 0.09 Å for the backbone atoms (1.21 ± 0.13 Å for all non-hydrogen atoms). The three major helices superimpose with a backbone RMSD of 0.48 ± 0.10 Å (0.99 ± 0.11 Å for non-hydrogen atoms). Based on this solution structure, homology models were constructed for five other DEBS ACP domains. Comparison of their steric and electrostatic surfaces at the putative interaction interface (centered on helix II) suggests a model for protein,protein recognition of ACP domains, consistent with the previously observed specificity. Site-directed mutagenesis experiments indicate that two of the identified residues influence the specificity of ACP recognition. [source]

Conserved Amino Acid Residues Correlating With Ketoreductase Stereospecificity in Modular Polyketide Synthases

CHEMBIOCHEM, Issue 7 2003
Patrick Caffrey Dr.
Getting down to specifics: Key amino acid residues were found to correlate with ketoreductase domain stereospecificity in modular polyketide synthases. These residues may allow alcohol stereochemistry (see scheme; ACP, acyl carrier protein) in polyketides to be predicted from ketoreductase sequences. The results also suggest that polyketide synthase dehydratase domains have a preference for 3hydroxyacyl substrates with the same alcohol stereochemistry as the (3R)-hydroxyacyl chains used by dehydratases in fatty acid synthases. [source]