scholarly journals Identification and Characterization of Catabolic para-Nitrophenol 4-Monooxygenase and para-Benzoquinone Reductase from Pseudomonas sp. Strain WBC-3

2009 ◽  
Vol 191 (8) ◽  
pp. 2703-2710 ◽  
Author(s):  
Jun-Jie Zhang ◽  
Hong Liu ◽  
Yi Xiao ◽  
Xian-En Zhang ◽  
Ning-Yi Zhou

ABSTRACT Pseudomonas sp. strain WBC-3 utilizes para-nitrophenol (PNP) as a sole source of carbon, nitrogen, and energy. In order to identify the genes involved in this utilization, we cloned and sequenced a 12.7-kb fragment containing a conserved region of NAD(P)H:quinone oxidoreductase genes. Of the products of the 13 open reading frames deduced from this fragment, PnpA shares 24% identity to the large component of a 3-hydroxyphenylacetate hydroxylase from Pseudomonas putida U and PnpB is 58% identical to an NAD(P)H:quinone oxidoreductase from Escherichia coli. Both PnpA and PnpB were purified to homogeneity as His-tagged proteins, and they were considered to be a monomer and a dimer, respectively, as determined by gel filtration. PnpA is a flavin adenine dinucleotide-dependent single-component PNP 4-monooxygenase that converts PNP to para-benzoquinone in the presence of NADPH. PnpB is a flavin mononucleotide-and NADPH-dependent p-benzoquinone reductase that catalyzes the reduction of p-benzoquinone to hydroquinone. PnpB could enhance PnpA activity, and genetic analyses indicated that both pnpA and pnpB play essential roles in PNP mineralization in strain WBC-3. Furthermore, the pnpCDEF gene cluster next to pnpAB shares significant similarities with and has the same organization as a gene cluster responsible for hydroquinone degradation (hapCDEF) in Pseudomonas fluorescens ACB (M. J. Moonen, N. M. Kamerbeek, A. H. Westphal, S. A. Boeren, D. B. Janssen, M. W. Fraaije, and W. J. van Berkel, J. Bacteriol. 190:5190-5198, 2008), suggesting that the genes involved in PNP degradation are physically linked.

2001 ◽  
Vol 183 (18) ◽  
pp. 5262-5267 ◽  
Author(s):  
Daniel Baitsch ◽  
Cristinel Sandu ◽  
Roderich Brandsch ◽  
Gabor L. Igloi

ABSTRACT A 27,690-bp gene cluster involved in the degradation of the plant alkaloid nicotine was characterized from the plasmid pAO1 ofArthrobacter nicotinovorans. The genes of the heterotrimeric, molybdopterin cofactor (MoCo)-, flavin adenine dinucleotide (FAD)-, and [Fe-S] cluster-dependent 6-hydroxypseudooxynicotine (ketone) dehydrogenase (KDH) were identified within this cluster. The gene of the large MoCo subunit of KDH was located 4,266 bp from the FAD and [Fe-S] cluster subunit genes. Deduced functions of proteins encoded by open reading frames (ORFs) of the cluster were correlated to individual steps in nicotine degradation. The gene for 2,6-dihydroxypyridine 3-hydroxylase was cloned and expressed in Escherichia coli. The purified homodimeric enzyme of 90 kDa contained 2 mol of tightly bound FAD per mol of dimer. Enzyme activity was strictly NADH-dependent and specific for 2,6-dihydroxypyridine. 2,3-Dihydroxypyridine and 2,6-dimethoxypyridine acted as irreversible inhibitors. Additional ORFs were shown to encode hypothetical proteins presumably required for holoenzyme assembly, interaction with the cell membrane, and transcriptional regulation, including a MobA homologue predicted to be specific for the synthesis of the molybdopterin cytidine dinucleotide cofactor.


2007 ◽  
Vol 190 (3) ◽  
pp. 1064-1071 ◽  
Author(s):  
Noboru Nakata ◽  
Nagatoshi Fujiwara ◽  
Takashi Naka ◽  
Ikuya Yano ◽  
Kazuo Kobayashi ◽  
...  

ABSTRACT The Mycobacterium avium complex is distributed ubiquitously in the environment. It is an important cause of pulmonary and extrapulmonary diseases in humans and animals. The species in this complex produce polar glycopeptidolipids (GPLs); of particular interest is their serotype-specific antigenicity. Several reports have described that GPL structure may play an important role in bacterial physiology and pathogenesis and in the host immune response. Recently, we determined the complete structure of the GPL derived from Mycobacterium intracellulare serotype 7 and characterized the serotype 7 GPL-specific gene cluster. The structure of serotype 7 GPL closely resembles that of serotype 12 GPL, except for O methylation. In the present study, we isolated and characterized the serotype 12-specific gene cluster involved in glycosylation of the GPL. Ten open reading frames (ORFs) and one pseudogene were observed in the cluster. The genetic organization of the serotype 12-specific gene cluster resembles that of the serotype 7-specific gene cluster, but two novel ORFs (orfA and orfB) encoding putative methyltransferases are present in the cluster. Functional analyses revealed that orfA and orfB encode methyltransferases that synthesize O-methyl groups at the C-4 position in the rhamnose residue next to the terminal hexose and at the C-3 position in the terminal hexose, respectively. Our results show that these two methyltransferase genes determine the structural difference of serotype 12-specific GPL from serotype 7-specific GPL.


2007 ◽  
Vol 74 (4) ◽  
pp. 1281-1283 ◽  
Author(s):  
Donald A. Comfort ◽  
Chung-Jung Chou ◽  
Shannon B. Conners ◽  
Amy L. VanFossen ◽  
Robert M. Kelly

ABSTRACT Bioinformatics analysis and transcriptional response information for Pyrococcus furiosus grown on α-glucans led to the identification of a novel isomaltase (PF0132) representing a new glycoside hydrolase (GH) family, a novel GH57 β-amylase (PF0870), and an extracellular starch-binding protein (1,141 amino acids; PF1109-PF1110), in addition to several other putative α-glucan-processing enzymes.


Pathogens ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 57 ◽  
Author(s):  
Kadriye Çağlayan ◽  
Vahid Roumi ◽  
Mona Gazel ◽  
Eminur Elçi ◽  
Mehtap Acioğlu ◽  
...  

High throughput sequencing of total RNA isolated from symptomatic leaves of a sweet cherry tree (Prunus avium cv. 0900 Ziraat) from Turkey identified a new member of the genus Robigovirus designated cherry virus Turkey (CVTR). The presence of the virus was confirmed by electron microscopy and overlapping RT-PCR for sequencing its whole-genome. The virus has a ssRNA genome of 8464 nucleotides which encodes five open reading frames (ORFs) and comprises two non-coding regions, 5′ UTR and 3′ UTR of 97 and 296 nt, respectively. Compared to the five most closely related robigoviruses, RdRp, TGB1, TGB2, TGB3 and CP share amino acid identities ranging from 43–53%, 44–60%, 39–43%, 38–44% and 45–50%, respectively. Unlike the four cherry robigoviruses, CVTR lacks ORFs 2a and 5a. Its genome organization is therefore more similar to African oil palm ringspot virus (AOPRV). Using specific primers, the presence of CVTR was confirmed in 15 sweet cherries and two sour cherries out of 156 tested samples collected from three regions in Turkey. Among them, five samples were showing slight chlorotic symptoms on the leaves. It seems that CVTR infects cherry trees with or without eliciting obvious symptoms, but these data should be confirmed by bioassays in woody and possible herbaceous hosts in future studies.


1999 ◽  
Vol 181 (10) ◽  
pp. 3155-3163 ◽  
Author(s):  
M. Gita Bangera ◽  
Linda S. Thomashow

The polyketide metabolite 2,4-diacetylphloroglucinol (2,4-DAPG) is produced by many strains of fluorescent Pseudomonas spp. with biocontrol activity against soilborne fungal plant pathogens. Genes required for 2,4-DAPG synthesis by P. fluorescensQ2-87 are encoded by a 6.5-kb fragment of genomic DNA that can transfer production of 2,4-DAPG to 2,4-DAPG-nonproducing recipientPseudomonas strains. In this study the nucleotide sequence was determined for the 6.5-kb fragment and flanking regions of genomic DNA from strain Q2-87. Six open reading frames were identified, four of which (phlACBD) comprise an operon that includes a set of three genes (phlACB) conserved between eubacteria and archaebacteria and a gene (phlD) encoding a polyketide synthase with homology to chalcone and stilbene synthases from plants. The biosynthetic operon is flanked on either side by phlEand phlF, which code respectively for putative efflux and regulatory (repressor) proteins. Expression in Escherichia coli of phlA, phlC, phlB, andphlD, individually or in combination, identified a novel polyketide biosynthetic pathway in which PhlD is responsible for the production of monoacetylphloroglucinol (MAPG). PhlA, PhlC, and PhlB are necessary to convert MAPG to 2,4-DAPG, and they also may function in the synthesis of MAPG.


1999 ◽  
Vol 181 (19) ◽  
pp. 6214-6219 ◽  
Author(s):  
Rosario Muñoz ◽  
Marta Mollerach ◽  
Rubens López ◽  
Ernesto García

ABSTRACT The complete nucleotide sequence of the capsular gene cluster (cap8) responsible for the biosynthesis of the capsular polysaccharide of Streptococcus pneumoniae type 8 has been determined. The cap8 gene cluster, located between the genes dexB and aliA, is composed of 12 open reading frames. A 14.7-kb DNA fragment embracing the cap8genes was sufficient to transform an unencapsulated type 3 S. pneumoniae strain to a strain with the type 8 capsule. A possible scenario for the evolution of pneumococcal types 2 and 8 is outlined.


2003 ◽  
Vol 185 (22) ◽  
pp. 6513-6521 ◽  
Author(s):  
Sharon Melamed ◽  
Edna Tanne ◽  
Raz Ben-Haim ◽  
Orit Edelbaum ◽  
David Yogev ◽  
...  

ABSTRACT Phytoplasmas are unculturable, insect-transmissible plant pathogens belonging to the class Mollicutes. To be transmitted, the phytoplasmas replicate in the insect body and are delivered to the insect's salivary glands, from where they are injected into the recipient plant. Because phytoplasmas cannot be cultured, any attempt to recover phytoplasmal DNA from infected plants or insects has resulted in preparations with a large background of host DNA. Thus, studies of the phytoplasmal genome have been greatly hampered, and aside from the rRNA genes, only a few genes have hitherto been isolated and characterized. We developed a unique method to obtain host-free phytoplasmal genomic DNA from the insect vector's saliva, and we demonstrated the feasibility of this method by isolating and characterizing 78 new putative phytoplasmal open reading frames and their deduced proteins. Based on the newly accumulated information on phytoplasmal genes, preliminary characteristics of the phytoplasmal genome are discussed.


2009 ◽  
Vol 76 (1) ◽  
pp. 40-47 ◽  
Author(s):  
Guangyun Lin ◽  
William H. Tepp ◽  
Christina L. Pier ◽  
Mark J. Jacobson ◽  
Eric A. Johnson

ABSTRACT Clostridium botulinum subtype A2 possesses a botulinum neurotoxin type A (BoNT/A) gene cluster consisting of an orfX cluster containing open reading frames (ORFs) of unknown functions. To better understand the association between the BoNT/A2 complex proteins, first, the orfX cluster proteins (ORFX1, ORFX3, P47, and the middle part of NTNH) from C. botulinum A2 strain Kyoto F and NTNH of A1 strain ATCC 3502 were expressed by using either an Escherichia coli or a C. botulinum expression system. Polyclonal antibodies against individual orfX cluster proteins were prepared by immunizing a rabbit and mice against the expressed proteins. Antibodies were then utilized as probes to determine which of the A2 orfX cluster genes were expressed in the native A2 culture. N-terminal protein sequencing was also employed to specifically detect ORFX2. Results showed that all of the neurotoxin cluster proteins, except ORFX1, were expressed in the A2 culture. A BoNT/A2 toxin complex (TC) was purified which showed that C. botulinum A2 formed a medium-size (300-kDa) TC composed of BoNT/A2 and NTNH without any of the other OrfX cluster proteins. NTNH subtype-specific immunoreactivity was also discovered, allowing for the differentiation of subtypes based on cluster proteins associated with BoNT.


2010 ◽  
Vol 76 (13) ◽  
pp. 4201-4206 ◽  
Author(s):  
Takashi Kawasaki ◽  
Reiko Hirashima ◽  
Tomoka Maruta ◽  
Haruka Sato ◽  
Ayumi Maeda ◽  
...  

ABSTRACT Streptomyces sp. strain 2238-SVT4 produces hatomarubigins A, B, C, and D, which belong to the angucycline family. Among them, hatomarubigin D has a unique dimeric structure with a methylene linkage. PCR using aromatase and cyclase gene-specific primers identified the hrb gene cluster for angucycline biosynthesis in Streptomyces sp. 2238-SVT4. The cluster consisted of 30 open reading frames, including those for the minimal polyketide synthase, ketoreductase, aromatase, cyclase, O-methyltransferase, oxidoreductase, and oxygenase genes. Expression of a part of the gene cluster containing hrbR1 to hrbX in Streptomyces lividans TK23 resulted in the production of hatomarubigins A, B, and C. Hatomarubigin D was obtained from the conversion of hatomarubigin C by a purified enzyme encoded by hrbY, among the remaining genes.


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