scholarly journals Characterization of the Gene Cassette Required for Biosynthesis of the (α1→6)-LinkedN-Acetyl-d-Mannosamine-1-Phosphate Capsule of Serogroup A Neisseria meningitidis

1998 ◽  
Vol 180 (6) ◽  
pp. 1533-1539 ◽  
Author(s):  
John S. Swartley ◽  
Li-Jun Liu ◽  
Yoon K. Miller ◽  
Larry E. Martin ◽  
Srilatha Edupuganti ◽  
...  

ABSTRACT The (α1→6)-linkedN-acetyl-d-mannosamine-1-phosphate meningococcal capsule of serogroup A Neisseria meningitidisis biochemically distinct from the sialic acid-containing capsules produced by other disease-associated meningococcal serogroups (e.g., B, C, Y, and W-135). We defined the genetic cassette responsible for expression of the serogroup A capsule. The cassette comprised a 4,701-bp nucleotide sequence located between the outer membrane capsule transporter gene, ctrA, and galE, encoding the UDP-glucose-4-epimerase. Four open reading frames (ORFs) not found in the genomes of the other meningococcal serogroups were identified. The first serogroup A ORF was separated from ctrA by a 218-bp intergenic region. Reverse transcriptase (RT) PCR and primer extension studies of serogroup A mRNA showed that all four ORFs were cotranscribed in the opposite orientation to ctrA and that transcription of the ORFs was initiated from the intergenic region by a ς-70-type promoter that overlapped the ctrA promoter. The first ORF exhibited 58% amino acid identity with the UDP-N-acetyl-d-glucosamine (UDP-GlcNAc) 2-epimerase of Escherichia coli, which is responsible for the conversion of UDP-GlcNAc into UDP-N-acetyl-d-mannosamine. Polar or nonpolar mutagenesis of each of the ORFs resulted in an abrogation of serogroup A capsule production as determined by colony immunoblots and enzyme-linked immunosorbent assay. Replacement of the serogroup A biosynthetic gene cassette with a serogroup B cassette by transformation resulted in capsule switching from a serogroup A capsule to a serogroup B capsule. These data indicate that assembly of the serogroup A capsule likely begins with monomeric UDP-GlcNAc and requires proteins encoded by three other genes found in the serogroup A N. meningitidis-specific operon located betweenctrA and galE.

1996 ◽  
Vol 40 (5) ◽  
pp. 1254-1256 ◽  
Author(s):  
H Hächler ◽  
P Santanam ◽  
F H Kayser

A novel, probably chromosomally encoded, aminoglycoside phosphotransferase gene was cloned on a 2,996-bp PstI fragment from Pseudomonas aeruginosa and designated aph (3')-IIb. It coded for a protein of 268 amino acids that showed 51.7% amino acid identity with APH (3')-II [APH(3') is aminoglycoside-3' phosphotransferase] from Tn5. Two other open reading frames on the cloned fragment showed homology to a signal-transducing system in P. aeruginosa.


2003 ◽  
Vol 71 (12) ◽  
pp. 6712-6720 ◽  
Author(s):  
Yih-Ling Tzeng ◽  
Corie Noble ◽  
David S. Stephens

ABSTRACT The genetic basis for biosynthesis of the (α1→4)-linked N-acetyl-d-glucosamine 1-phosphate capsule of Neisseria meningitidis serogroup X was defined. The biosynthesis gene cassette was a ∼4.2-kb region located between ctrA of the capsule transport operon and galE, which encodes the UDP-glucose-4-epimerase. This location was identical to the locations of the biosynthesis cassettes in other meningococcal serogroups. Three open reading frames unique to meningococcus serogroup X were identified. Deletion-insertion mutation and colony immunoblotting confirmed that these three genes were essential for serogroup X capsule expression, and the genes were designated xcbA, xcbB, and xcbC (serogroup X capsule biosynthesis). Reverse transcriptase PCR indicated that the xcbABC genes form an operon and are cotranscribed divergently from ctrA. XcbA exhibited 52% amino acid similarity to SacB, the putative capsule polymerase of meningococcus serogroup A, suggesting that it plays a role as the serogroup X capsule polymerase. An IS1016 element was found within the intergenic region separating ctrA and xcbA in multiple strains, and this element did not interfere with capsule expression.


Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 27
Author(s):  
Jun Kwon ◽  
Sang Guen Kim ◽  
Hyoun Joong Kim ◽  
Sib Sankar Giri ◽  
Sang Wha Kim ◽  
...  

The increasing emergence of antimicrobial resistance has become a global issue. Therefore, many researchers have attempted to develop alternative antibiotics. One promising alternative is bacteriophage. In this study, we focused on a jumbo-phage infecting Salmonella isolated from exotic pet markets. Using a Salmonella strain isolated from reptiles as a host, we isolated and characterized the novel jumbo-bacteriophage pSal-SNUABM-04. This phage was investigated in terms of its morphology, host infectivity, growth and lysis kinetics, and genome. The phage was classified as Myoviridae based on its morphological traits and showed a comparatively wide host range. The lysis efficacy test showed that the phage can inhibit bacterial growth in the planktonic state. Genetic analysis revealed that the phage possesses a 239,626-base pair genome with 280 putative open reading frames, 76 of which have a predicted function and 195 of which have none. By genome comparison with other jumbo phages, the phage was designated as a novel member of Machinavirus composed of Erwnina phages.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Chaitanya Erady ◽  
Adam Boxall ◽  
Shraddha Puntambekar ◽  
N. Suhas Jagannathan ◽  
Ruchi Chauhan ◽  
...  

AbstractUncharacterized and unannotated open-reading frames, which we refer to as novel open reading frames (nORFs), may sometimes encode peptides that remain unexplored for novel therapeutic opportunities. To our knowledge, no systematic identification and characterization of transcripts encoding nORFs or their translation products in cancer, or in any other physiological process has been performed. We use our curated nORFs database (nORFs.org), together with RNA-Seq data from The Cancer Genome Atlas (TCGA) and Genotype-Expression (GTEx) consortiums, to identify transcripts containing nORFs that are expressed frequently in cancer or matched normal tissue across 22 cancer types. We show nORFs are subject to extensive dysregulation at the transcript level in cancer tissue and that a small subset of nORFs are associated with overall patient survival, suggesting that nORFs may have prognostic value. We also show that nORF products can form protein-like structures with post-translational modifications. Finally, we perform in silico screening for inhibitors against nORF-encoded proteins that are disrupted in stomach and esophageal cancer, showing that they can potentially be targeted by inhibitors. We hope this work will guide and motivate future studies that perform in-depth characterization of nORF functions in cancer and other diseases.


2013 ◽  
Vol 195 (17) ◽  
pp. 3819-3826 ◽  
Author(s):  
S. Gong ◽  
Z. Yang ◽  
L. Lei ◽  
L. Shen ◽  
G. Zhong

2021 ◽  
Author(s):  
Yang Sun ◽  
Yan qiong Li ◽  
Wen han Dong ◽  
Ai li Sun ◽  
Ning wei Chen ◽  
...  

Abstract The complete genome of the dsRNA virus isolated from Rhizoctonia solani AG-1 IA 9–11 (designated as Rhizoctonia solani dsRNA virus 11, RsRV11 ) were determined. The RsRV11 genome was 9,555 bp in length, contained three conserved domains, SMC, PRK and RT-like super family, and encoded two non-overlapping open reading frames (ORFs). ORF1 potentially coded for a 204.12 kDa predicted protein, which shared low but significant amino acid sequence identities with the putative protein encoded by Rhizoctonia solani RNA virus HN008 (RsRV-HN008) ORF1. ORF2 potentially coded for a 132.41 kDa protein which contained the conserved motifs of the RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis indicated that RsRV11 was clustered with RsRV-HN008 in a separate clade independent of other virus families. It implies that RsRV11, along with RsRV-HN008 possibly a new fungal virus taxa closed to the family Megabirnaviridae, and RsRV11 is a new member of mycoviruses.


2012 ◽  
Vol 78 (24) ◽  
pp. 8719-8734 ◽  
Author(s):  
Mariángeles Briggiler Marcó ◽  
Josiane E. Garneau ◽  
Denise Tremblay ◽  
Andrea Quiberoni ◽  
Sylvain Moineau

ABSTRACTWe characterized twoLactobacillus plantarumvirulent siphophages, ATCC 8014-B1 (B1) and ATCC 8014-B2 (B2), previously isolated from corn silage and anaerobic sewage sludge, respectively. Phage B2 infected two of the eightL. plantarumstrains tested, while phage B1 infected three. Phage adsorption was highly variable depending on the strain used. Phage defense systems were found in at least twoL. plantarumstrains, LMG9211 and WCSF1. The linear double-stranded DNA genome of thepac-type phage B1 had 38,002 bp, a G+C content of 47.6%, and 60 open reading frames (ORFs). Surprisingly, the phage B1 genome has 97% identity with that ofPediococcus damnosusphage clP1 and 77% identity with that ofL. plantarumphage JL-1; these phages were isolated from sewage and cucumber fermentation, respectively. The double-stranded DNA (dsDNA) genome of thecos-type phage B2 had 80,618 bp, a G+C content of 36.9%, and 127 ORFs with similarities to those ofBacillusandLactobacillusstrains as well as phages. Some phage B2 genes were similar to ORFs fromL. plantarumphage LP65 of theMyoviridaefamily. Additionally, 6 tRNAs were found in the phage B2 genome. Protein analysis revealed 13 (phage B1) and 9 (phage B2) structural proteins. To our knowledge, this is the first report describing such high identity between phage genomes infecting different genera of lactic acid bacteria.


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.


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