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Purification, crystallization and preliminary X-ray diffraction analysis of enoyl-acyl carrier protein reductase (FabK) from Streptococcus mutans strain UA159.

ABSTRACT: A triclosan-resistant flavoprotein termed FabK is the sole enoyl-acyl carrier protein reductase in Streptococcus pneumoniae and Streptococcus mutans. In this study, FabK from S. mutans strain UA159 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.40 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P6(2), with unit-cell parameters a = b = 105.79, c = 44.15 Å. The asymmetric unit contained one molecule, with a corresponding V(M) of 2.05 Å(3) Da(-1) and a solvent content of 39.9%.

SUBMITTER: Kim TO

PROVIDER: S-EPMC3310533 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature

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Purification, crystallization and preliminary X-ray diffraction analysis of enoyl-acyl carrier protein reductase (FabK) from Streptococcus mutans strain UA159.

Kim Tae-O TO Im Dong-Won DW Jung Ha Yun HY Kwon Seong Jung SJ Heo Yong-Seok YS

Acta crystallographica. Section F, Structural biology and crystallization communications 20120222 Pt 3

A triclosan-resistant flavoprotein termed FabK is the sole enoyl-acyl carrier protein reductase in Streptococcus pneumoniae and Streptococcus mutans. In this study, FabK from S. mutans strain UA159 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 2.40 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P6(2), with unit-cell parameters a = b = 105.79, c = 44.15 Å. The asymmetric unit contained one molecule, wit ...[more]

PMID: 22442225

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Crystallization and preliminary X-ray analysis of enoyl-acyl carrier protein reductase (FabK) from Streptococcus pneumoniae.

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Characterization of Streptococcus pneumoniae enoyl-(acyl-carrier protein) reductase (FabK).

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Crystallization and preliminary X-ray crystallographic studies of enoyl-acyl carrier protein reductase (FabI) from Psuedomonas aeruginosa.

Project description:During fatty-acid biosynthesis, enoyl-acyl carrier protein (enoyl-ACP) reductase catalyzes the reduction of trans-2-enoyl-ACP to fully saturated acyl-ACP via the ubiquitous fatty-acid synthase system. NADH-dependent enoyl-ACP reductase (FabI) from Pseudomonas aeruginosa has been purified and crystallized as an apoenzyme and in a complex form with NADH and triclosan. Triclosan is an inhibitor of FabI and forms a stable ternary complex in the presence of NADH. The crystals of native and complexed FabI diffracted to resolutions of 2.6 and 1.8 Å, respectively. The crystals both belonged to space group P2(1), with unit-cell parameters a = 117.32, b = 155.844, c = 129.448 Å, β = 111.061° for the native enzyme and a = 64.784, b = 107.573, c = 73.517 Å, β = 116.162° for the complex. Preliminary molecular replacement further confirmed the presence of four tetramers of native FabI and one tetramer of the complex in the asymmetric unit, corresponding to Matthews coefficients (V(M)) of 2.46 and 2.05 Å(3) Da(-1) and solvent contents of 50.1 and 40.1%, respectively.

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Structural Basis for Cyclopropanation by a Unique Enoyl-Acyl Carrier Protein Reductase.

Project description:The natural product curacin A, a potent anticancer agent, contains a rare cyclopropane group. The five enzymes for cyclopropane biosynthesis are highly similar to enzymes that generate a vinyl chloride moiety in the jamaicamide natural product. The structural biology of this remarkable catalytic adaptability is probed with high-resolution crystal structures of the curacin cyclopropanase (CurF ER), an in vitro enoyl reductase (JamJ ER), and a canonical curacin enoyl reductase (CurK ER). The JamJ and CurK ERs catalyze NADPH-dependent double bond reductions typical of enoyl reductases (ERs) of the medium-chain dehydrogenase reductase (MDR) superfamily. Cyclopropane formation by CurF ER is specified by a short loop which, when transplanted to JamJ ER, confers cyclopropanase activity on the chimeric enzyme. Detection of an adduct of NADPH with the model substrate crotonyl-CoA provides indirect support for a recent proposal of a C2-ene intermediate on the reaction pathway of MDR enoyl-thioester reductases.

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Structural characterization of Porphyromonas gingivalis enoyl-ACP reductase II (FabK).

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