scholarly journals Molecular Characterization of the Complete 23F Capsular Polysaccharide Locus of Streptococcus pneumoniae

1998 ◽  
Vol 180 (19) ◽  
pp. 5273-5278 ◽  
Author(s):  
Mario Ramirez ◽  
Alexander Tomasz

ABSTRACT The complete DNA sequence of the capsular locus 23F ofStreptococcus pneumoniae is presented. The 18.6-kbcps23f locus is composed of 18 open reading frames flanked at the 5′ and 3′ ends by the genes dexB andaliA, an arrangement similar to those of some of the other identified cps loci.

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 44 (9) ◽  
pp. 2585-2587 ◽  
Author(s):  
Maria Santagati ◽  
Francesco Iannelli ◽  
Marco R. Oggioni ◽  
Stefania Stefani ◽  
Gianni Pozzi

ABSTRACT The mef(A) gene from a clinical isolate ofStreptococcus pneumoniae exhibiting the M-type resistance to macrolides was found to be part of the 7,244-bp chromosomal element Tn1207.1, which contained 8 open reading frames.orf2 encodes a resolvase/invertase, and orf5 is a homolog of the macrolide-streptogramin B resistance genemsr(SA).


2000 ◽  
Vol 68 (10) ◽  
pp. 5742-5748 ◽  
Author(s):  
Kwon-Sam Park ◽  
Tetsuya Iida ◽  
Yoshiharu Yamaichi ◽  
Tomohito Oyagi ◽  
Koichiro Yamamoto ◽  
...  

ABSTRACT We have demonstrated that possession of the gene for thermostable direct hemolysin-related hemolysin (trh) coincides with the presence of the urease gene among clinical Vibrio parahaemolyticus strains and that the location of the two genes are in close proximity on the chromosome. Here, we cloned and sequenced the 15,754-bp DNA region containing the trh gene and the gene cluster for urease production from the chromosome of clinicalV. parahaemolyticus (TH3996). We found 16 open reading frames (ORFs) and a lower G+C content (41%) compared with the total genome of this bacterium (46 to 47%). The ure cluster consisted of eight genes, namely, ureDABCEFG andureR. ureR was located 5.2 kb upstream of the other seven genes in the opposite direction. The genetic organization and sequences of the ure genes resembled those found in Proteus mirabilis. Between ureR and the other uregenes, there were five ORFs, which are homologous with the nickel transport operon (nik) of Escherichia coli. We disrupted each of the ureR, ureC, andnikD genes in TH3996 by homologous recombination and analyzed the phenotype of the mutants. In the presence of urea these mutant strains had dramatically less urease activity than the strain they were derived from. Disruption of ureR,nikD, or ureC, however, had no effect on TRH production. The DNA region containing the trh,nik, and ure genes was found in onlytrh-positive strains and not in Kanagawa phenomenon-positive and environmental V. parahaemolyticusstrains. At the end of the region, an insertion sequence-like element existed. These results suggest that the DNA region was introduced intoV. parahaemolyticus in the past through a mechanism mediated by insertion sequences. This is the first reported case that the genes for an ATP-binding cassette-type nickel transport system, which may play a role in nickel transport through bacterial cytoplasmic membrane, are located adjacent to the ure cluster on the genome of an organism.


2010 ◽  
Vol 7 (1) ◽  
Author(s):  
Jae in Lee ◽  
Gyu-Cheol Lee ◽  
Young hee Oh ◽  
Young ki Lee ◽  
Min young Kim ◽  
...  

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.


2011 ◽  
Vol 286 (41) ◽  
pp. 35813-35822 ◽  
Author(s):  
Jinghua Yang ◽  
Moon H. Nahm ◽  
C. Allen Bush ◽  
John O. Cisar

Streptococcus pneumoniae serogroup 10 includes four cross-reactive capsular polysaccharide (CPS) serotypes (10F, 10A, 10B, and 10C). In the present study, the structures of CPS10B and CPS10C were determined by chemical and high resolution NMR methods to define the features of each serotype. Both CPS10C and CPS10F had β1–6-linked Galf branches formed from the termini of linear repeating units by wzy-dependent polymerization through the 4-OH of subterminal GalNAc. The only difference between these polysaccharides was the wcrC-dependent α1–2 or wcrF-dependent α1–4 linkages between Gal and ribitol-5-phosphate. The presence of one linkage or the other also distinguished the repeating units of CPS10B and CPS10A. However, whereas these polysaccharides both had β1–3-linked Galf branches linked to GalNAc, only CPS10A had additional β1–6-linked Galp branches. These Galp branches and the reaction of a CPS10A-specific monoclonal antibody were eliminated by deletion of wcrG from the cps10A locus. In contrast, deletion of this gene from the cps10B locus had no effect on the structure of CPS10B, thereby identifying wcrG as a pseudogene in this serotype. The β1–3-linked Galf branches of CPS10A and CPS10B were eliminated by deletion of wcrD from each corresponding cps locus. Deletion of this gene also eliminated wcrG-dependent β1–6-linked Galp branches from CPS10A, thereby identifying WcrG as a branching enzyme that acts on the product of WcrD. These findings provide a complete view of the molecular, structural, and antigenic features of CPS serogroup 10, as well as insight into the possible emergence of new serotypes.


2008 ◽  
Vol 74 (21) ◽  
pp. 6792-6796 ◽  
Author(s):  
Shanmuga Sozhamannan ◽  
Michael McKinstry ◽  
Shannon M. Lentz ◽  
Matti Jalasvuori ◽  
Farrell McAfee ◽  
...  

ABSTRACT The genome sequence of a Bacillus anthracis-specific clear plaque mutant phage, AP50c, contains 31 open reading frames spanning 14,398 bp, has two mutations compared to wild-type AP50t, and has a colinear genome architecture highly similar to that of gram-positive Tectiviridae phages. Spontaneous AP50c-resistant B. anthracis mutants exhibit a mucoid colony phenotype.


2001 ◽  
Vol 67 (11) ◽  
pp. 5225-5232 ◽  
Author(s):  
Gang Dai ◽  
Ping Su ◽  
Gwen E. Allison ◽  
Bruce L. Geller ◽  
Ping Zhu ◽  
...  

ABSTRACT This study reports on the identification and characterization of a novel abortive infection system, AbiU, from Lactococcus lactis. AbiU confers resistance to phages from the three main industrially relevant lactococcal phage species: c2, 936, and P335. The presence of AbiU reduced the efficiency of plaquing against specific phage from each species as follows: 3.7 × 10−1, 1.0 × 10−2, and 1.0 × 10−1, respectively. abiU involves two open reading frames,abiU1 (1,772 bp) and abiU2 (1,019 bp). Evidence indicates that AbiU1 is responsible for phage resistance and that AbiU2 may downregulate phage resistance against 936 and P335 type phages but not c2 type phage. AbiU appeared to delay transcription of both phage 712 and c2, with the effect being more marked on phage c2.


2021 ◽  
Author(s):  
Jie Zhong ◽  
Ze Zhong Yang ◽  
Xin Yang ◽  
Zhao Jiang Guo ◽  
Wen Xie ◽  
...  

Abstract Here we reported the molecular characterization of two novel mycoviruses co-infected in a plant pathogenic fungus, Nigrospora sphaerica that were designated as Nigrospora sphaerica fusarivirus 1 (NsFV1) and Nigrospora sphaerica partitivirus 1 (NsPV1), respectively. NsFV1 has an undivided genome of 6,147 bp, excluding the polyA tail, and was predicted to contain two nonoverlapping open reading frames (ORF1 and 2). The larger ORF1 encoded a polyprotein containing a conserved RNA-dependent RNA polymerase (RdRp) and a helicase domain that have functions for RNA replication, and the smaller ORF2 encoded a putative protein with an unknown function. The NsPV1 was consists of two genome segments, which were in lengths of 1,796 bp and 1,455 bp, respectively. Each of the two dsRNAs had a single ORF and were deduced to encode proteins with homology to viral RdRp and coat protein (CP), respectively, in the family Partitiviridae. Phylogenetic analysis showed that NsFV1 was placed within the newly proposed family Fusariviridae, while NsPV1 was belonging to the genus Gammapartitivirus in the family Partitiviridae. This was the first description of mycovirses infected the fungus N. sphaerica.


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