Water Significantly Changes the Ring-Cleavage Process During Aqueous Photooxidation of Toluene

Comamonas testosteroni TA441 degrades steroids aerobically via aromatization of the A-ring accompanied by B-ring cleavage, followed by D- and C-ring cleavage. We previously revealed major enzymes and intermediate compounds in A,B-ring cleavage, β-oxidation cycle of the cleaved B-ring, and partial C,D-ring cleavage process. Here, we elucidated the C-ring cleavage and the β-oxidation cycle that follows. ScdL1L2, a 3-ketoacid Coenzyme A (CoA) transferase which belongs to the SugarP_isomerase superfamily, was thought to cleave the C-ring of 9-oxo-1,2,3,4,5,6,10,19-octanor-13,17-secoandrost-8(14)-ene-7,17-dioic acid-CoA ester, the key intermediate compound in the degradation of 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid (3aα-H-4α [3′-propionic acid]-7aβ-methylhexahydro-1,5-indanedione; HIP)-CoA ester in the previous study; however, this study suggested that ScdL1L2 is the isomerase of the derivative with a hydroxyl group at C-14 which cleaves C ring. The subsequent ring-cleaved product was indicated to be converted to 4-methyl-5-oxo-octane-1,8-dioic acid-CoA ester mainly by ORF33-encoded CoA-transferase (named ScdJ), followed by dehydrogenation by ORF21 and 22-encoded acyl-CoA dehydrogenase (named ScdM1M2). Then a water molecule is added by ScdN for further degradation by β-oxidation. ScdN is considered to catalyze the last reaction in C,D-ring degradation by the enzymes encoded in the steroid degradation gene cluster tesB to tesR.

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Cleavage of the Epimines of 1,6-Anhydrohexoses with Fluoride Anion

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc20052075 ◽

2005 ◽

Vol 70 (12) ◽

pp. 2075-2085 ◽

Cited By ~ 5

Author(s):

Jiří Kroutil ◽

Klára Jeništová

Keyword(s):

Fluoride Anion ◽

Ring Cleavage ◽

Protecting Group ◽

Reaction Conditions ◽

Aziridine Ring ◽

Cleavage Reactions ◽

Derivatives Of ◽

Fluoro Derivatives

Aziridine ring cleavage reactions of five N-nosylepimines (2-6) having D-talo, D-galacto, D-manno, and D-allo configurations with potassium hydrogendifluoride under various reaction conditions have been performed. The cleavage regioselectively afforded diaxial isomers of vicinal amino-fluoro derivatives of 1,6-anhydro-β-D-gluco- and mannopyranose 7-11 in 51-94% yields. Removal of 2-nitrobenzenesulfonyl protecting group with benzenethiol has been attempted in the case of compound 10.

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Metagenomic analysis of aromatic ring-cleavage mechanism in nano-Fe3O4@activated coke enhanced bio-system for coal pyrolysis wastewater treatment

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2021.125387 ◽

2021 ◽

pp. 125387

Author(s):

Mengqi Zheng ◽

Hongjun Han ◽

Jingxin Shi ◽

Zhengwen Zhang ◽

Wencheng Ma ◽

...

Keyword(s):

Wastewater Treatment ◽

Aromatic Ring ◽

Metagenomic Analysis ◽

Ring Cleavage ◽

Coal Pyrolysis ◽

Aromatic Ring Cleavage ◽

Activated Coke ◽

Nano Fe3o4

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Synthesis of Medium-Sized Cyclic Amines by Selective Ring Cleavage of Sulfonylated Bicyclic Amines

Organic Letters ◽

10.1021/ol0162163 ◽

2001 ◽

Vol 3 (19) ◽

pp. 2957-2960 ◽

Cited By ~ 27

Author(s):

Fátima Iradier ◽

Ramón Gómez Arrayás ◽

Juan Carlos Carretero

Keyword(s):

Ring Cleavage ◽

Cyclic Amines

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Novel Myosin Heavy Chain Kinase Involved in Disassembly of Myosin II Filaments and Efficient Cleavage in MitoticDictyostelium Cells

Molecular Biology of the Cell ◽

10.1091/mbc.e02-04-0228 ◽

2002 ◽

Vol 13 (12) ◽

pp. 4333-4342 ◽

Cited By ~ 18

Author(s):

Akira Nagasaki ◽

Go Itoh ◽

Shigehiko Yumura ◽

Taro Q.P. Uyeda

Keyword(s):

Myosin Heavy Chain ◽

Heavy Chain ◽

Myosin Ii ◽

Kinase Domain ◽

Cleavage Furrow ◽

Wild Type ◽

Daughter Cells ◽

Cleavage Process ◽

Interphase Cells ◽

Myosin Heavy Chain Kinase

We have cloned a full-length cDNA encoding a novel myosin II heavy chain kinase (mhckC) from Dictyostelium. Like other members of the myosin heavy chain kinase family, themhckC gene product, MHCK C, has a kinase domain in its N-terminal half and six WD repeats in the C-terminal half. GFP-MHCK C fusion protein localized to the cortex of interphase cells, to the cleavage furrow of mitotic cells, and to the posterior of migrating cells. These distributions of GFP-MHCK C always corresponded with that of myosin II filaments and were not observed in myosin II-null cells, where GFP-MHCK C was diffusely distributed in the cytoplasm. Thus, localization of MHCK C seems to be myosin II-dependent. Cells lacking the mhckC gene exhibited excessive aggregation of myosin II filaments in the cleavage furrows and in the posteriors of the daughter cells once cleavage was complete. The cleavage process of these cells took longer than that of wild-type cells. Taken together, these findings suggest MHCK C drives the disassembly of myosin II filaments for efficient cytokinesis and recycling of myosin II that occurs during cytokinesis.

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Genetic Investigation of the Catabolic Pathway for Degradation of Abietane Diterpenoids by Pseudomonas abietaniphilaBKME-9

Journal of Bacteriology ◽

10.1128/jb.182.13.3784-3793.2000 ◽

2000 ◽

Vol 182 (13) ◽

pp. 3784-3793 ◽

Cited By ~ 39

Author(s):

Vincent J. J. Martin ◽

William W. Mohn

Keyword(s):

Gene Cluster ◽

Sequence Similarity ◽

Open Reading Frames ◽

Ring Cleavage ◽

Catabolic Pathway ◽

Transcriptional Fusion ◽

Abietane Diterpenoids ◽

Genes Encoding ◽

Dna Fragment ◽

Reading Frames

ABSTRACT We have cloned and sequenced the dit gene cluster encoding enzymes of the catabolic pathway for abietane diterpenoid degradation by Pseudomonas abietaniphila BKME-9. Thedit gene cluster is located on a 16.7-kb DNA fragment containing 13 complete open reading frames (ORFs) and 1 partial ORF. The genes ditA1A2A3 encode the α and β subunits and the ferredoxin of the dioxygenase which hydroxylates 7-oxodehydroabietic acid to 7-oxo-11,12-dihydroxy-8,13-abietadien acid. The dioxygenase mutant strain BKME-941 (ditA1::Tn5) did not grow on nonaromatic abietanes, and transformed palustric and abietic acids to 7-oxodehydroabietic acid in cell suspension assays. Thus, nonaromatic abietanes are aromatized prior to further degradation. Catechol 2,3-dioxygenase activity of xylEtranscriptional fusion strains showed induction of ditA1and ditA3 by abietic, dehydroabietic, and 7-oxodehydroabietic acids, which support the growth of strain BKME-9, as well as by isopimaric and 12,14-dichlorodehydroabietic acids, which are diterpenoids that do not support the growth of strain BKME-9. In addition to the aromatic-ring-hydroxylating dioxygenase genes, thedit cluster includes ditC, encoding an extradiol ring cleavage dioxygenase, and ditR, encoding an IclR-type transcriptional regulator. Although ditR is not strictly required for the growth of strain BKME-9 on abietanes, aditR::Kmr mutation in aditA3::xylE reporter strain demonstrated that it encodes an inducer-dependent transcriptional activator of ditA3. An ORF with sequence similarity to genes encoding permeases (ditE) is linked with genes involved in abietane degradation.

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