Development of a strictly regulated xylose-induced expression system in Streptomyces.

Background: Genetic tools including constitutive and inducible promoters have been developed over the last few decades for strain engineering in Streptomyces. Inducible promoters are useful for controlling gene expression, however only a limited number are applicable to Streptomyces. The aim of this study is to develop a controllable protein expression system based on an inducible promoter using sugar inducer, which has not yet been widely applied in Streptomyces.

Structural basis for high substrate-binding affinity and enantioselectivity of 3-quinuclidinone reductase AtQR.

(R)-3-Quinuclidinol, a useful compound for the synthesis of various pharmaceuticals, can be enantioselectively produced from 3-quinuclidinone by 3-quinuclidinone reductase. Recently, a novel NADH-dependent 3-quinuclidionone reductase (AtQR) was isolated from Agrobacterium tumefaciens, and showed much higher substrate-binding affinity (>100 fold) than the reported 3-quinuclidionone reductase (RrQR) from Rhodotorula rubra. Here, we report the crystal structure of AtQR at 1.

Structural basis of stereospecific reduction by quinuclidinone reductase.

Chiral molecule (R)-3-quinuclidinol, a valuable compound for the production of various pharmaceuticals, is efficiently synthesized from 3-quinuclidinone by using NADPH-dependent 3-quinuclidinone reductase (RrQR) from Rhodotorula rubra. Here, we report the crystal structure of RrQR and the structure-based mutational analysis. The enzyme forms a tetramer, in which the core of each protomer exhibits the α/β Rossmann fold and contains one molecule of NADPH, whereas the characteristic substructures of a small lobe and a variable loop are localized around the substrate-binding site.

Expression, purification, crystallization and X-ray analysis of 3-quinuclidinone reductase from Agrobacterium tumefaciens.

(R)-3-Quinuclidinol is a useful chiral building block for the synthesis of various pharmaceuticals and can be produced from 3-quinuclidinone by asymmetric reduction. A novel 3-quinuclidinone reductase from Agrobacterium tumefaciens (AtQR) catalyzes the stereospecific reduction of 3-quinuclidinone to (R)-3-quinuclidinol with NADH as a cofactor. Recombinant AtQR was overexpressed in Escherichia coli, purified and crystallized with NADH using the sitting-drop vapour-diffusion method at 293 K.

A beta-l-Arabinopyranosidase from Streptomyces avermitilis is a novel member of glycoside hydrolase family 27.

Arabinogalactan proteins (AGPs) are a family of plant cell surface proteoglycans and are considered to be involved in plant growth and development. Because AGPs are very complex molecules, glycoside hydrolases capable of degrading AGPs are powerful tools for analyses of the AGPs. We previously reported such enzymes from Streptomyces avermitilis.

Crystallization and preliminary X-ray analysis of the NADPH-dependent 3-quinuclidinone reductase from Rhodotorula rubra.

(R)-3-Quinuclidinol is a useful compound that is applicable to the synthesis of various pharmaceuticals. The NADPH-dependent carbonyl reductase 3-quinuclidinone reductase from Rhodotorula rubra catalyzes the stereospecific reduction of 3-quinuclidinone to (R)-3-quinuclidinol and is expected to be utilized in industrial production of this alcohol. 3-Quinuclidinone reductase from R.

Crystallization and preliminary crystallographic analysis of beta-L-arabinopyranosidase from Streptomyces avermitilis NBRC14893.

Beta-L-arabinopyranosidase from Streptomyces avermitilis NBRC14893 is a monomeric protein consisting of a catalytic domain belonging to glycosyl hydrolase family 27, an unknown domain and a substrate-binding domain belonging to carbohydrate-binding module family 13. The complete enzyme (residues 45-658) has successfully been cloned and homologously expressed in the Streptomyces expression system. beta-L-Arabinopyranosidase was crystallized by the sitting-drop vapour-diffusion method.

Stereoselective synthesis of (R)-3-quinuclidinol through asymmetric reduction of 3-quinuclidinone with 3-quinuclidinone reductase of Rhodotorula rubra.

A novel nicotinamide adenine dinucleotide phosphate-dependent carbonyl reductase, 3-quinuclidinone reductase, was isolated from Rhodotorula rubra JCM3782. The enzyme catalyzes the asymmetric reduction of 3-quinuclidinone to (R)-3-quinuclidinol. The gene encoding the enzyme was also cloned and sequenced.