scholarly journals Genetic and Antigenic Diversity of the Surface Protective Antigen Proteins of Erysipelothrix rhusiopathiae

2007 ◽  
Vol 14 (7) ◽  
pp. 813-820 ◽  
Author(s):  
Ho To ◽  
Shinya Nagai

ABSTRACTThe surface protective antigen (Spa) protein ofErysipelothrix rhusiopathiaehas been shown to be highly immunogenic and is a potential candidate for a new vaccine against erysipelas. In this study, we cloned and sequencedspagenes from allE. rhusiopathiaeserovar reference strains as well as from a serovar 18 strain which was not classified as any species in the genusErysipelothrix.Sequence analysis revealed that the Spa proteins could be classified into three molecular species, including SpaA, which was previously found in serovars 1a and 2, and the newly designated SpaB and SpaC proteins. The SpaA protein is produced byE. rhusiopathiaeserovars 1a, 1b, 2, 5, 8, 9, 12, 15, 16, 17, and N, the SpaB protein is produced byE. rhusiopathiaeserovars 4, 6, 11, 19, and 21, and the SpaC protein is produced only by serovar 18. The amino acid sequence similarity was high among members of each Spa type (96 to 99%) but low between different Spa types (∼60%). The greatest diversity in Spa proteins was found in the N-terminal half of the molecule (50 to 57% similarity), which was shown to be involved in immunoprotection. Coinciding with this, immunoblot analysis revealed that rabbit antisera specific to each Spa reacted strongly with the homologous Spa protein but weakly with heterologous Spa proteins. A mouse cross-protection study showed that the three recombinant Spa (rSpa) proteins elicited complete protection against challenge with homologous strains but that the level of protection against challenge with heterologous strains varied depending on the rSpa protein used for immunization. Our study is the first to demonstrate sequence and antigenic diversity in Spa proteins and to indicate that rSpaC may be the most promising antigen for use as a vaccine component because of its broad cross-protectiveness.

2010 ◽  
Vol 17 (12) ◽  
pp. 1991-1997 ◽  
Author(s):  
Ho To ◽  
Shuichi Someno ◽  
Shinya Nagai ◽  
Tomohiro Koyama ◽  
Tetsuji Nagano

ABSTRACTPreviously, we showed that surface protective antigen (Spa) proteins ofErysipelothrix rhusiopathiaecan be classified into three molecular species—SpaA, SpaB, and SpaC—and that SpaC is the most broadly cross-protective antigen among the three Spa proteins. In this study, we examined the ability of the α-helical domain, which comprises the N-terminal half of SpaC, to elicit cross-protective immunity in mice and pigs. Mice actively immunized with the full-length protein (rSpaC664) or the α-helical domain (rSpaC427), but not the C-terminal domain (rSpaC253), were protected against challenge withE. rhusiopathiaeserovars 1a, 2, 6, 19, and 18 expressing heterologous (SpaA or SpaB) and homologous (SpaC) Spas. The α-helical domain seemed to provide better protection than rSpaC664, although the differences did not reach statistical significance. Similarly, mice passively immunized with rabbit anti-rSpaC664 or anti-rSpaC427 sera, but not anti-rSpaC253 serum, were protected from challenge with various serovars. Pigs immunized with SpaC427 also developed specific antibodies against Spa proteins and were protected from challenge with the highly virulent heterologousE. rhusiopathiaestrain Fujisawa (serovar 1a). Taken together, these results demonstrate for the first time the striking protective efficacy of the α-helical domain-mediated immunization in both mice and pigs, thereby highlighting its utility as the most promising candidate for the development of a safe and effective vaccine against erysipelas.


Author(s):  
Ai-Hua Wang ◽  
Lan Yang ◽  
Xin-Zhuan Yao ◽  
Xiao-Peng Wen

AbstractPhosphoethanolamine N-methyltransferase (PEAMTase) catalyzes the methylation of phosphoethanolamine to produce phosphocholine and plays an important role in the abiotic stress response. Although the PEAMT genes has been isolated from many species other than pitaya, its role in the drought stress response has not yet been fully elucidated. In the present study, we isolated a 1485 bp cDNA fragment of HpPEAMT from pitaya (Hylocereus polyrhizus). Phylogenetic analysis showed that, during its evolution, HpPEAMT has shown a high degree of amino acid sequence similarity with the orthologous genes in Chenopodiaceae species. To further investigate the function of HpPEAMT, we generated transgenic tobacco plants overexpressing HpPEAMT, and the transgenic plants accumulated significantly more glycine betaine (GB) than did the wild type (WT). Drought tolerance trials indicated that, compared with those of the wild-type (WT) plants, the roots of the transgenic plants showed higher drought tolerance ability and exhibited improved drought tolerance. Further analysis revealed that overexpression of HpPEAM in Nicotiana tabacum resulted in upregulation of transcript levels of GB biosynthesis-related genes (NiBADH, NiCMO and NiSDC) in the leaves. Furthermore, compared with the wild-type plants, the transgenic tobacco plants displayed a significantly lower malondialdehyde (MDA) accumulation and higher activities of the superoxide dismutase (SOD) and peroxidase (POD) antioxidant enzymes under drought stress. Taken together, our results suggested that HpPEAMT enhanced the drought tolerance of transgenic tobacco.


2017 ◽  
Vol 91 (6) ◽  
Author(s):  
Yi-Jiun Pan ◽  
Tzu-Lung Lin ◽  
Ching-Ching Chen ◽  
Yun-Ting Tsai ◽  
Yi-Hsiang Cheng ◽  
...  

ABSTRACT The genome of the multihost bacteriophage ΦK64-1, capable of infecting Klebsiella capsular types K1, K11, K21, K25, K30, K35, K64, and K69, as well as new capsular types KN4 and KN5, was analyzed and revealed that 11 genes (S1-1, S1-2, S1-3, S2-1, S2-2, S2-3, S2-4, S2-5, S2-6, S2-7, and S2-8) encode proteins with amino acid sequence similarity to tail fibers/spikes or lyases. S2-5 previously was shown to encode a K64 capsule depolymerase (K64dep). Specific capsule-degrading activities of an additional eight putative capsule depolymerases (S2-4 against K1, S1-1 against K11, S1-3 against K21, S2-2 against K25, S2-6 against K30/K69, S2-3 against K35, S1-2 against KN4, and S2-1 against KN5) was demonstrated by expression and purification of the recombinant proteins. Consistent with the capsular type-specific depolymerization activity of these gene products, phage mutants of S1-2, S2-2, S2-3, or S2-6 lost infectivity for KN4, K25, K35, or K30/K69, respectively, indicating that capsule depolymerase is crucial for infecting specific hosts. In conclusion, we identified nine functional capsule depolymerase-encoding genes in a bacteriophage and correlated activities of the gene products to all ten hosts of this phage, providing an example of type-specific host infection mechanisms in a multihost bacteriophage. IMPORTANCE We currently identified eight novel capsule depolymerases in a multihost Klebsiella bacteriophage and correlated the activities of the gene products to all hosts of this phage, providing an example of carriage of multiple depolymerases in a phage with a wide capsular type host spectrum. Moreover, we also established a recombineering system for modification of Klebsiella bacteriophage genomes and demonstrated the importance of capsule depolymerase for infecting specific hosts. Based on the powerful tool for modification of phage genome, further studies can be conducted to improve the understanding of mechanistic details of Klebsiella phage infection. Furthermore, the newly identified capsule depolymerases will be of great value for applications in capsular typing.


2007 ◽  
Vol 57 (2) ◽  
pp. 250-254 ◽  
Author(s):  
Jun Gu ◽  
Hua Cai ◽  
Su-Lin Yu ◽  
Ri Qu ◽  
Bin Yin ◽  
...  

Two novel strains, SL014B61AT and SL014B11A, were isolated from an oil-polluted saline soil from Gudao in the coastal Shengli Oilfield, eastern China. Cells of strains SL014B61AT and SL014B11A were motile, Gram-negative and rod-shaped. Growth occurred at NaCl concentrations of between 0 and 15 % and at temperatures of between 10 and 45 °C. Strain SL014B61AT had Q9 as the major respiratory quinone and C16 : 0 (21.2 %), C18 : 1ω9c (20.3 %), C16 : 1ω7c (7.3 %) and C16 : 1ω9c (6.4 %) as predominant fatty acids. The G+C content of the DNA was 57.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SL014B61AT belonged to the genus Marinobacter in the class Gammaproteobacteria. Strain SL014B61AT showed the highest 16S rRNA gene sequence similarity with Marinobacter bryozoorum (97.9 %) and showed 97.8 % sequence similarity to Marinobacter lipolyticus. DNA–DNA relatedness to the reference strains Marinobacter bryozoorum and Marinobacter lipolyticus was 35.5 % and 33.8 %, respectively. On the basis of these data, it is proposed that strains SL014B61AT and SL014B11A represent a novel species, Marinobacter gudaonensis sp. nov. The type strain is strain SL014B61AT (=DSM 18066T=LMG 23509T=CGMCC 1.6294T).


1992 ◽  
Vol 288 (1) ◽  
pp. 117-121 ◽  
Author(s):  
E P Ko ◽  
H Akatsuka ◽  
H Moriyama ◽  
A Shinmyo ◽  
Y Hata ◽  
...  

To elucidate the reaction mechanism of xylanase, the identification of amino acids essential for its catalysis is of importance. Studies have indicated the possibility that the reaction mechanism of xylanase is similar to that of hen's egg lysozyme, which involves acidic amino acid residues. On the basis of this assumption, together with the three-dimensional structure of Bacillus pumilus xylanase and its amino acid sequence similarity to other xylanases of different origins, three acidic amino acids, namely Asp-21, Glu-93 and Glu-182, were selected for site-directed mutagenesis. The Asp residue was altered to either Ser or Glu, and the Glu residues to Ser or Asp. The purified mutant xylanases D21E, D21S, E93D, E93S, E182D and E182S showed single protein bands of about 26 kDa on SDS/PAGE. C.d. spectra of these mutant enzymes show no effect on the secondary structure of xylanase, except that of D21E, which shows a little variation. Furthermore, mutations of Glu-93 and Glu-182 resulted in a drastic decrease in the specific activity of xylanase as compared with mutation of Asp-21. On the basis of these results we propose that Glu-93 and Glu-182 are the best candidates for the essential catalytic residues of xylanase.


2021 ◽  
Author(s):  
Saowapha Surawut ◽  
Sorasak Nak-aim ◽  
Chutapa Kunsook ◽  
Laddawan Kamhaengkul ◽  
Pornpimon Kanjanavas ◽  
...  

Abstract Ascomycetes mushrooms are fungi that produce ascospores in asci and some with perithecia. Not only they have a role of decomposer in ecology but also produced some bioactive compound, anti-microbial activity, and cytotoxicity. This study aims to explore the diversity of ascomycetes mushroom species in para rubber plantations and to identify them by morphological and sequence analysis of the internal transcribed spacer (ITS) region. The results found ascomycetes mushroom consist of Trichoderma pezizoides (RP1, % identity 98.79, DQ835513.1), Daldinia eschscholtzii (RP2, % identity 100, MN310384.1), Cookeina sulcipes (RP3, % identity 98.44, KY094620.1), Cookeina garethjonesii (RP4, % identity 99.06, KY094622.1), Cookeina tricholoma (RP5, % identity 100, KY094619.1) and Xylaria terricola (RP6, % identity 88.42, MF577038.1). Most of the ascomycetes in this study have previously been described in Thailand except Xylaria terricola. Additionally, phylogenetic analysis of ascomycetes mushroom showed high genetic relatedness with reference strains. Therefore, the sequence similarity and phylogenetic analysis confirmed the identity of six ascomycetes mushroom species, and further study of bioactive compound from these mushrooms may be investigated for other applications.


1994 ◽  
Vol 196 (1) ◽  
pp. 93-108
Author(s):  
D K Kakuda ◽  
C L MacLeod

Recent advances have made possible the isolation of the genes and their cDNAs encoding Na(+)-independent amino acid transporters. Two classes of amino acid 'uniporters' have been isolated. One class contains the mCAT (murine cationic amino acid transporter) gene family that encodes proteins predicted to span the membrane 12-14 times and exhibits structural properties similar to the GLUT (glucose transporter) family and to other well-known transporters. The other class consists of two known genes, rBAT (related to B system amino acid transporters) and 4F2hc, that share amino acid sequence similarity with alpha-amylases and alpha-glucosidases. They are type II glycoproteins predicted to span the membrane only once, yet they mediate the Na(+)-independent transport of cationic and zwitterionic amino acids in Xenopus oocytes. Mutations in the human rBAT gene have been identified by Palacín and his co-workers in several families suffering from a heritable form of cystinuria. This important finding clearly establishes a key role for rBAT in cystine transport. The two classes of amino acid transporters are compared with the well-studied GLUT family of Na(+)-independent glucose transporters.


Sign in / Sign up

Export Citation Format

Share Document