A broad specificity β-propeller enzyme from Rhodopseudomonas palustris that hydrolyzes many lactones including γ-valerolactone.
A broad specificity β-propeller enzyme from Rhodopseudomonas palustris that hydrolyzes many lactones including γ-valerolactone.
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DOI：
10.1016/j.jbc.2022.102782
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发表时间：
2023-01
影响因子：
4.8
通讯作者：
Donohue, Timothy J.
中科院分区：
文献类型：
--
作者：
Hall, Benjamin W.;Bingman, Craig A.;Fox, Brian G.;Noguera, Daniel R.;Donohue, Timothy J.
内酯在生物学和工业环境中很普遍，但是缺乏有关将这些化合物代谢的酶的信息。随后的微生物转化为燃料和化学物质，尽管将GVL作为可再生溶液的生物量解构，但残留的GVL可能对微生物发酵有毒。 Ca2+依赖性的酶来自Rhodopseudomonas palustris（RPA3624），并表明它可以水解脂肪型和芳香族内酯和酯，包括GVL，包括GVL，并通过实验确定的sequections seque seque seque seque seque seque seque seque seque seque seque seque seque seque seque seque sequections rpa36262224偏爱疏水性底物。 β-螺旋体酶与磷酸盐，抑制剂或GVL和产物的混合物分别定义了一个活跃的位点，其中钙结合的水和钙结合的天冬氨酸和谷氨酸保留使我们与底物和产物密切接触。 WT和突变酶与结构见解相结合，告知了一种反应机制，该反应机制围绕着通过一般碱基催化和密切接触而促进的钙结合水分子的激活底物和潜在的中间体。
Lactones are prevalent in biological and industrial settings, yet there is a lack of information regarding enzymes used to metabolize these compounds. One compound, γ-valerolactone (GVL), is used as a solvent to dissolve plant cell walls into sugars and aromatic molecules for subsequent microbial conversion to fuels and chemicals. Despite the promise of GVL as a renewable solvent for biomass deconstruction, residual GVL can be toxic to microbial fermentation. Here, we identified a Ca2+-dependent enzyme from Rhodopseudomonas palustris (Rpa3624) and showed that it can hydrolyze aliphatic and aromatic lactones and esters, including GVL. Maximum-likelihood phylogenetic analysis of other related lactonases with experimentally determined substrate preferences shows that Rpa3624 separates by sequence motifs into a subclade with preference for hydrophobic substrates. Additionally, we solved crystal structures of this β-propeller enzyme separately with either phosphate, an inhibitor, or a mixture of GVL and products to define an active site where calcium-bound water and calcium-bound aspartic and glutamic acid residues make close contact with substrate and product. Our kinetic characterization of WT and mutant enzymes combined with structural insights inform a reaction mechanism that centers around activation of a calcium-bound water molecule promoted by general base catalysis and close contacts with substrate and a potential intermediate. Similarity of Rpa3624 with other β-propeller lactonases suggests this mechanism may be relevant for other members of this emerging class of versatile catalysts.
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影响因子：
4.8
作者：
Bar-Rogovsky, Hagit;Hugenmatter, Adrian;Tawfik, Dan S.
通讯作者：
Tawfik, Dan S.
影响因子：
6.5
作者：
Draganov, DI;Teiber, JF;La Du, BN
通讯作者：
La Du, BN
影响因子：
4.1
作者：
Fetzner, Susanne
通讯作者：
Fetzner, Susanne
影响因子：
4.8
作者：
Draganov, DI;Stetson, PL;La Du, BN
通讯作者：
La Du, BN
DOI：
10.1016/0006-3002(61)90289-x
发表时间：
1961-01-01
期刊：
BIOCHIMICA ET BIOPHYSICA ACTA
影响因子：
--
作者：
BUBLITZ, C;LEHNINGER, AL
通讯作者：
LEHNINGER, AL