scholarly journals Characterization of the Bacillus subtilis ywsC Gene, Involved in γ-Polyglutamic Acid Production

2002 ◽  
Vol 184 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Yuji Urushibata ◽  
Shinji Tokuyama ◽  
Yasutaka Tahara

ABSTRACT The genes required for γ-polyglutamic acid (PGA) production were cloned from Bacillus subtilis IFO16449, a strain isolated from fermented soybeans. There were four open reading frames in the cloned 4.2-kb DNA fragment, and they were almost identical to those in the ywsC and ywtABC genes of B. subtlis 168. Northern blot analysis showed that the four genes constitute an operon. Three genes, ywsC, ywtA, and ywtB, were disrupted to determine which gene plays a central role in PGA biosynthesis. No PGA was produced in ΔywsC and ΔywtA strains, indicating that both of these genes are essential for PGA production. To clarify the function of the YwsC protein, histidine-tagged YwsC (YwsC-His) was produced in the ΔywsC strain and purified from the lysozyme-treated lysate of the transformant by Ni-nitrilotriacetic acid affinity chromatography. Western blot analysis revealed that the YwsC-His protein consists of two subunits, the 44-kDa and 33-kDa proteins, which are encoded by in-phase overlapping in the ywsC gene. 14C-labeled PGA was synthesized by the purified proteins from l-[14C]-glutamate in the presence of ATP and MnCl2, through an acylphosphate intermediate, indicating that the ywsC gene encodes PGA synthetase (EC 6.3.2), a crucial enzyme in PGA biosynthesis.

2000 ◽  
Vol 182 (19) ◽  
pp. 5521-5529 ◽  
Author(s):  
Hao Jiang ◽  
Kathleen E. Kendrick

ABSTRACT In the presence of cefoxitin, which inhibits septum formation during sporulation, Streptomyces griseus is unable to sporulate, retaining the sonication sensitivity of nonsporulating hyphae. Cefoxitin- and sonication-resistant mutant SKK2600 was isolated and showed many morphological differences from its parental strain. A 3.6-kb DNA fragment that complemented the mutations of SKK2600 contained two open reading frames (ORFs), either of which could complement SKK2600. One ORF, designated ssfR, encoded a protein containing a potential DNA-binding helix-turn-helix motif close to its N terminus. SsfR is similar to members of a large family of transcriptional regulators, particularly IclR of Escherichia coli. The second ORF was identified as ssgA, a previously described sporulation gene from S. griseus (S. Kawamoto and J. C. Ensign, Actinomycetology 9:136–151, 1995). A point mutation of C to T seven nucleotides upstream of the UGA stop codon of ssfR was responsible for the phenotype of isolated mutant strain SKK2600. Surprisingly, this mutation should not change the primary structure of SsfR. The ssfR andssgA disruption mutants were constructed and showed the “white” mutant phenotype, with some growth medium dependence. In addition, the ssfR null mutant sporulated ectopically in phosphate starvation medium.


Acta Naturae ◽  
2016 ◽  
Vol 8 (1) ◽  
pp. 117-125 ◽  
Author(s):  
V. A. Chernukhin ◽  
D. A. Gonchar ◽  
M. A. Abdurashitov ◽  
O. A. Belichenko ◽  
V. S. Dedkov ◽  
...  

Putative open reading frames of MD-endonucleases have been identified in Enterobacteria genomes as a result of the search for amino acid sequences homologous to MD-endonuclease BisI. A highly conserved DNA primary structure of these open reading frames in different genera of Enterobacteria (Escherichia, Klebsiella and Cronobacter) has allowed researchers to create primers for PCR screening, which was carried out on Enterobacteria DNA collected from natural sources. The DNA fragment, about 440 bp in length, was amplified by use of the genomic DNA of a wild E.coli LM N17 strain as a template and was inserted into the pMTL22 vector. Endonuclease activity was detected in an E.coli ER 2267 strain transformed with the obtained construction. A new enzyme named ElmI was purified by chromatographic techniques from the recombinant strain biomass. It was discovered that similarly to BisI this enzyme specifically cleaves the methylated DNA sequence 5-GCNGC- 3 before the central nucleotide N if this sequence contains two 5-methylcytosines. However, unlike BisI, ElmI more efficiently cleaves this sequence if more than two cytosine residues are methylated.


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.


2000 ◽  
Vol 182 (12) ◽  
pp. 3467-3474 ◽  
Author(s):  
Teresa M. Barbosa ◽  
Stuart B. Levy

ABSTRACT In Escherichia coli, the MarA protein controls expression of multiple chromosomal genes affecting resistance to antibiotics and other environmental hazards. For a more-complete characterization of the mar regulon, duplicate macroarrays containing 4,290 open reading frames of the E. coli genome were hybridized to radiolabeled cDNA populations derived frommar-deleted and mar-expressing E. coli. Strains constitutively expressing MarA showed altered expression of more than 60 chromosomal genes: 76% showed increased expression and 24% showed decreased expression. Although some of the genes were already known to be MarA regulated, the majority were newly determined and belonged to a variety of functional groups. Some of the genes identified have been associated with iron transport and metabolism; other genes were previously known to be part of thesoxRS regulon. Northern blot analysis of selected genes confirmed the results obtained with the macroarrays. The findings reveal that the mar locus mediates a global stress response involving one of the largest networks of genes described.


Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Brad L. Ericson ◽  
Darby J. Carlson ◽  
Kimberly A. Carlson

Nora virus is a single stranded RNA picorna-like virus with four open reading frames (ORFs). The coding potentials of the ORFs are not fully characterized, but ORF3 and ORF4 are believed to encode the capsid proteins (VP3, VP4a, VP4b, and VP4c) comprising the virion. To determine the polypeptide composition of Nora virus virions, polypeptides from purified virus were compared to polypeptides detected in Nora virus infectedDrosophila melanogaster. Nora virus was purified from infected flies and used to challenge mice for the production of antisera.ORF3,ORF4a,ORF4b, andORF4cwere individually cloned and expressed inE. coli; resultant recombinant proteins purified and were used to make monospecific antisera. Antisera were evaluated via Western blot against whole virus particles and Nora virus infected fly lysates. Viral purification yielded two particle types with densities of ~1.31 g/mL (empty particles) and ~1.33 g/mL (complete virions). Comparison of purified virus polypeptide composition to Nora virus infectedD. melanogasterlysate showed the number of proteins in infected cell lysates is less than purified virus. Our results suggest the virion is composed of 6 polypeptides, VP3, VP4a, two forms of VP4b, and two forms of VP4c. This polypeptide composition is similar to other small RNA insect viruses.


2001 ◽  
Vol 183 (23) ◽  
pp. 6965-6970 ◽  
Author(s):  
José A. Horcajadas ◽  
Wilfried J. J. Meijer ◽  
Fernando Rojo ◽  
Margarita Salas

ABSTRACT Bacteriophage GA-1, which infects Bacillus sp. strain G1R, is evolutionarily related to phage φ29, which infectsBacillus subtilis. We report the characterization of several GA-1 promoters located at either end of its linear genome. Some of them are unique for GA-1 and drive the expression of open reading frames that have no counterparts in the genome of φ29 or related phages. These unique promoters are active at early infection times and are repressed at late times. In vitro transcription reactions revealed that the purified GA-1-encoded protein p6 represses the activity of these promoters, although the amount of p6 required to repress transcription was different for each promoter. The level of protein p6 produced in vivo increases rapidly during the first stage of the infection cycle. The protein p6 concentration may serve to modulate the expression of these early promoters as infection proceeds.


1998 ◽  
Vol 180 (11) ◽  
pp. 2968-2974 ◽  
Author(s):  
Hiromu Takamatsu ◽  
Yukari Chikahiro ◽  
Takeko Kodama ◽  
Hidekatsu Koide ◽  
Satoshi Kozuka ◽  
...  

ABSTRACT The spore coat of Bacillus subtilis has a unique morphology and consists of polypeptides of different sizes, whose synthesis and assembly are precisely regulated by a cascade of transcription factors and regulatory proteins. We examined the factors that regulate cotS gene expression and CotS assembly into the coat layer of B. subtilis by Northern blot and Western blot analysis. Transcription of cotS mRNA was not detected in sporulating cells of ςK and gerE mutants by Northern blot analysis. By Western blot analysis using anti-CotS antibody, CotS was first detected in protein samples solubilized from wild-type cells at 5 h after the start of sporulation. CotS was not detected in the vegetative cells and spores of a gerEmutant or in the spores of mutants deficient in ςE, ςF, ςG, or ςK. CotS was detected in the sporangium but not in the spores of a cotEmutant. The sequence of the promoter region of cotS was similar to the consensus sequences for binding of ςK and GerE. These results demonstrate that ςK and GerE are required for cotS expression and that CotE is essential for the assembly of CotS in the coat. Immunoelectron microscopic observation using anti-CotS antibody revealed that CotS is located within the spore coat, in particular in the inner coats of dormant spores.


1999 ◽  
Vol 181 (14) ◽  
pp. 4275-4284 ◽  
Author(s):  
C. R. Dean ◽  
C. V. Franklund ◽  
J. D. Retief ◽  
M. J. Coyne ◽  
K. Hatano ◽  
...  

ABSTRACT We previously cloned a genomic DNA fragment from the serogroup O11Pseudomonas aeruginosa strain PA103 that contained all genes necessary for O-antigen synthesis and directed the expression of serogroup O11 antigen on recombinant Escherichia coli andSalmonella. To elucidate the pathway of serogroup O11 antigen synthesis, the nucleotide sequence of the biosynthetic genes was determined. Eleven open reading frames likely to be involved in serogroup O11 O-antigen biosynthesis were identified and are designated in order as wzz PaO111 (wzz fromP. aeruginosa serogroup O11),wzx PaO11, wbjA,wzy PaO11, wbjB to wbjF,wbpL O11 and wbpM O11(wbpL and wbpM from serogroup O11). Consistent with previous descriptions of O-antigen biosynthetic gene loci, the entire region with the exception of wbpM O11 has a markedly reduced G+C content relative to the chromosomal average. WzyPaO11 shows no significant similarity at the protein or DNA sequence level to any database sequence and is very hydrophobic, with 10 to 12 putative transmembrane domains, both typical characteristics of O-antigen polymerases. A nonpolar chromosomal insertion mutation in wzy PaO11 in P. aeruginosa PA103 confirmed the identity of this gene. There is striking similarity between WbjBCDE and Cap(5/8)EFGL, involved in type 5 and type 8 capsule biosynthesis in Staphylococcus aureus. There is nearly total identity between wbpM O11and wbpM O5, previously shown by others to be present in all 20 P. aeruginosa serogroups. Using similarity searches, we have assigned functions to the proteins encoded by the PA103 O-antigen locus and present the potential steps in the pathway for the biosynthesis of P. aeruginosa serogroup O11 O antigen.


2001 ◽  
Vol 67 (10) ◽  
pp. 4805-4816 ◽  
Author(s):  
Hyung-Yeel Kahng ◽  
Juliana C. Malinverni ◽  
Michelle M. Majko ◽  
Jerome J. Kukor

ABSTRACT Burkholderia sp. strain JS150 is able to metabolize a wide range of alkyl-and chloroaromatic hydrocarbons through multiple, apparently redundant catabolic pathways. Previous research has shown that strain JS150 is able to synthesize enzymes for multiple upper pathways as well as multiple lower pathways to accommodate variously substituted catechols that result from degradation of complex mixtures of monoaromatic compounds. We report here the genetic organization and functional characterization of a gene cluster, designatedtbc (for toluene, benzene, and chlorobenzene utilization), which has been cloned as a 14.3-kb DNA fragment from strain JS150 into vector pRO1727. The cloned DNA fragment expressed in Pseudomonas aeruginosa PAO1c allowed the recombinant to grow on toluene or benzene and to transform chlorobenzene, trichloroethylene, phenol, and cresols. The tbc genes are organized into two divergently transcribed operons, tbc1 and tbc2, each comprised of six open reading frames. Similarity searches of databases revealed that the tbc1 and tbc2 genes showed significant homology to multicomponent cresol and phenol hydroxylases and to toluene and benzene monooxygenases, respectively. Deletion mutagenesis and product analysis were used to demonstrate thattbc2 plays a role in the initial catabolism of the unactivated alkyl- or chloroaromatic substrate and that thetbc1 gene products play a role in the catabolism of the first metabolite that results from transformation of the initial substrate. Phylogenetic analysis was used to compare individual components of these tbc monooxygenases with similar sequences in the databases. These results provide further evidence for the existence of multiple, functionally redundant alkyl- and chloroaromatic monooxygenases in strain JS150.


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