Faculty Opinions recommendation of 4-Hydroxyphenylacetate decarboxylases: properties of a novel subclass of glycyl radical enzyme systems.

2006 ◽  
Author(s):  
Wolfgang Buckel
Keyword(s):  
Glycyl Radical ◽  
Enzyme Systems ◽  
Glycyl Radical Enzyme

4-Hydroxyphenylacetate Decarboxylases:  Properties of a Novel Subclass of Glycyl Radical Enzyme Systems†

Biochemistry ◽  
2006 ◽  
Vol 45 (31) ◽  
pp. 9584-9592 ◽  
Author(s):  
Lihua Yu ◽  
Martin Blaser ◽  
Paula I. Andrei ◽  
Antonio J. Pierik ◽  
Thorsten Selmer
Keyword(s):  
Glycyl Radical ◽  
Enzyme Systems ◽  
Glycyl Radical Enzyme

scholarly journals Stable Isotope Fractionation Caused by Glycyl Radical Enzymes during Bacterial Degradation of Aromatic Compounds

2004 ◽  
Vol 70 (5) ◽  
pp. 2935-2940 ◽  
Author(s):  
Barbara Morasch ◽  
Hans H. Richnow ◽  
Andrea Vieth ◽  
Bernhard Schink ◽  
Rainer U. Meckenstock
Keyword(s):  
Stable Isotope ◽  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Toluene Degradation ◽  
Fractionation Factor ◽  
Glycyl Radical ◽  
Stable Isotope Fractionation ◽  
Benzylsuccinate Synthase ◽  
Glycyl Radical Enzyme

ABSTRACT Stable isotope fractionation was studied during the degradation of m-xylene, o-xylene, m-cresol, and p-cresol with two pure cultures of sulfate-reducing bacteria. Degradation of all four compounds is initiated by a fumarate addition reaction by a glycyl radical enzyme, analogous to the well-studied benzylsuccinate synthase reaction in toluene degradation. The extent of stable carbon isotope fractionation caused by these radical-type reactions was between enrichment factors (ε) of −1.5 and −3.9, which is in the same order of magnitude as data provided before for anaerobic toluene degradation. Based on our results, an analysis of isotope fractionation should be applicable for the evaluation of in situ bioremediation of all contaminants degraded by glycyl radical enzyme mechanisms that are smaller than 14 carbon atoms. In order to compare carbon isotope fractionations upon the degradation of various substrates whose numbers of carbon atoms differ, intrinsic ε (εintrinsic) were calculated. A comparison of εintrinsic at the single carbon atoms of the molecule where the benzylsuccinate synthase reaction took place with compound-specific ε elucidated that both varied on average to the same extent. Despite variations during the degradation of different substrates, the range of ε found for glycyl radical reactions was reasonably narrow to propose that rough estimates of biodegradation in situ might be given by using an average ε if no fractionation factor is available for single compounds.

Crystal Structure of a Glycyl Radical Enzyme from Archaeoglobus fulgidus

2006 ◽  
Vol 357 (1) ◽  
pp. 221-235 ◽  
Author(s):  
Lari Lehtiö ◽  
J. Günter Grossmann ◽  
Bashkim Kokona ◽  
Robert Fairman ◽  
Adrian Goldman
Keyword(s):  
Crystal Structure ◽  
Archaeoglobus Fulgidus ◽  
Glycyl Radical ◽  
Glycyl Radical Enzyme

scholarly journals Glycyl Radical Enzyme-Associated Microcompartments: Redox-Replete Bacterial Organelles

mBio ◽  
2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Bryan Ferlez ◽  
Markus Sutter ◽  
Cheryl A. Kerfeld
Keyword(s):  
Substrate Specificity ◽  
Pathogenic Bacteria ◽  
External Source ◽  
Redox Proteins ◽  
Physiological Importance ◽  
Bacterial Microcompartments ◽  
Glycyl Radical ◽  
Self Assembling ◽  
Glycyl Radical Enzyme ◽  
Protein Shell

ABSTRACTAn increasing number of microbes are being identified that organize catabolic pathways within self-assembling proteinaceous structures known as bacterial microcompartments (BMCs). Most BMCs are characterized by their singular substrate specificity and commonly employ B12-dependent radical mechanisms. In contrast, a less-well-known BMC type utilizes the B12-independent radical chemistry of glycyl radical enzymes (GREs). Unlike B12-dependent enzymes, GREs require an activating enzyme (AE) as well as an external source of electrons to generate an adenosyl radical and form their catalytic glycyl radical. Organisms encoding these glycyl radical enzyme-associated microcompartments (GRMs) confront the challenge of coordinating the activation and maintenance of their GREs with the assembly of a multienzyme core that is encapsulated in a protein shell. The GRMs appear to enlist redox proteins to either generate reductants internally or facilitate the transfer of electrons from the cytosol across the shell. Despite this relative complexity, GRMs are one of the most widespread types of BMC, with distinct subtypes to catabolize different substrates. Moreover, they are encoded by many prominent gut-associated and pathogenic bacteria. In this review, we will focus on the diversity, function, and physiological importance of GRMs, with particular attention given to their associated and enigmatic redox proteins.

scholarly journals Characterization of a Glycyl Radical Enzyme Bacterial Microcompartment Pathway inRhodobacter capsulatus

2018 ◽  
Vol 201 (5) ◽  
Author(s):  
Heidi S. Schindel ◽  
Jonathan A. Karty ◽  
James B. McKinlay ◽  
Carl E. Bauer
Keyword(s):  
Gene Cluster ◽  
Gas Chromatography Mass Spectrometry ◽  
Vitamin B ◽  
Metabolic Reaction ◽  
Enzymatic Reactions ◽  
Bisphosphate Carboxylase ◽  
Glycyl Radical ◽  
Glycyl Radical Enzyme

ABSTRACTBacterial microcompartments (BMCs) are large (∼100-nm) protein shells that encapsulate enzymes, their substrates, and cofactors for the purposes of increasing metabolic reaction efficiency and protecting cells from toxic intermediates. The best-studied microcompartment is the carbon-fixing carboxysome that encapsulates ribulose-1,5-bisphosphate carboxylase and carbonic anhydrase. Other well-known BMCs include the Pdu and Eut BMCs, which metabolize 1,2-propanediol and ethanolamine, respectively, with vitamin B12-dependent diol dehydratase enzymes. Recent bioinformatic analyses identified a new prevalent type of BMC, hypothesized to utilize vitamin B12-independent glycyl radical enzymes to metabolize substrates. Here we use genetic and metabolic analyses to undertakein vivocharacterization of the newly identified glycyl radical enzyme microcompartment 3 (GRM3) class of microcompartment clusters. Transcriptome sequencing analyses showed that the microcompartment gene cluster in the genome of the purple photosynthetic bacteriumRhodobacter capsulatuswas expressed under dark anaerobic respiratory conditions in the presence of 1,2-propanediol. High-performance liquid chromatography and gas chromatography-mass spectrometry analyses showed that enzymes coded by this cluster metabolized 1,2-propanediol into propionaldehyde, propanol, and propionate. Surprisingly, the microcompartment pathway did not protect these cells from toxic propionaldehyde under the conditions used in this study, with buildup of this intermediate contributing to arrest of cell growth. We further show that expression of microcompartment genes is regulated by a two-component system located downstream of the microcompartment cluster.IMPORTANCEBMCs are protein shells that are designed to compartmentalize enzymatic reactions that require either sequestration of a substrate or the sequestration of toxic intermediates. Due to their ability to compartmentalize reactions, BMCs have also become attractive targets for bioengineering novel enzymatic reactions. Despite these useful features, little is known about the biochemistry of newly identified classes of BMCs. In this study, we have undertaken genetic andin vivometabolic analyses of the newly identified GRM3 gene cluster.

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