کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5504469 1536287 2017 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Structure and biochemistry of phenylacetaldehyde dehydrogenase from the Pseudomonas putida S12 styrene catabolic pathway
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Structure and biochemistry of phenylacetaldehyde dehydrogenase from the Pseudomonas putida S12 styrene catabolic pathway
چکیده انگلیسی
Phenylacetaldehyde dehydrogenase catalyzes the NAD+-dependent oxidation of phenylactealdehyde to phenylacetic acid in the styrene catabolic and detoxification pathway of Pseudomonas putida (S12). Here we report the structure and mechanistic properties of the N-terminally histidine-tagged enzyme, NPADH. The 2.83 Å X-ray crystal structure is similar in fold to sheep liver cytosolic aldehyde dehydrogenase (ALDH1), but has unique set of intersubunit interactions and active site tunnel for substrate entrance. In solution, NPADH occurs as 227 kDa homotetramer. It follows a sequential reaction mechanism in which NAD+ serves as both the leading substrate and homotropic allosteric activator. In the absence of styrene monooxygenase reductase, which regenerates NAD+ from NADH in the first step of styrene catabolism, NPADH is inhibited by a ternary complex involving NADH, product, and phenylacetaldehyde, substrate. Each oligomerization domain of NPADH contains a six-residue insertion that extends this loop over the substrate entrance tunnel of a neighboring subunit, thereby obstructing the active site of the adjacent subunit. This feature could be an important factor in the homotropic activation and product inhibition mechanisms. Compared to ALDH1, the substrate channel of NPADH is narrower and lined with more aromatic residues, suggesting a means for enhancing substrate specificity.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Archives of Biochemistry and Biophysics - Volume 616, 15 February 2017, Pages 47-58
نویسندگان
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