کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10755582 1050376 2014 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structural basis for high substrate-binding affinity and enantioselectivity of 3-quinuclidinone reductase AtQR
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Structural basis for high substrate-binding affinity and enantioselectivity of 3-quinuclidinone reductase AtQR
چکیده انگلیسی
(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 1.72 Å. Three NADH-bound protomers and one NADH-free protomer form a tetrameric structure in an asymmetric unit of crystals. NADH not only acts as a proton donor, but also contributes to the stability of the α7 helix. This helix is a unique and functionally significant part of AtQR and is related to form a deep catalytic cavity. AtQR has all three catalytic residues of the short-chain dehydrogenases/reductases family and the hydrophobic wall for the enantioselective reduction of 3-quinuclidinone as well as RrQR. An additional residue on the α7 helix, Glu197, exists near the active site of AtQR. This acidic residue is considered to form a direct interaction with the amine part of 3-quinuclidinone, which contributes to substrate orientation and enhancement of substrate-binding affinity. Mutational analyses also support that Glu197 is an indispensable residue for the activity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 446, Issue 4, 18 April 2014, Pages 911-915
نویسندگان
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