scholarly journals Salmonella enterica Serovar Paratyphi C Carries an Inactive Shufflon

2004 ◽  
Vol 72 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Connie K. P. Tam ◽  
Jim Hackett ◽  
Christina Morris
Keyword(s):  
Typhoid Fever ◽  
Base Pair ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Terminal Region ◽  
Inverted Repeats ◽  
Single Base ◽  
Single Base Pair ◽  
Self Association ◽  
Base Pair Insertion

ABSTRACT Salmonella enterica serovar Typhi uses type IVB pili to facilitate bacterial self-association, but only when the PilV proteins (potential minor pilus proteins) are not synthesized. This pilus-mediated event may be important in typhoid fever pathogenesis. We initially show that S. enterica serovar Paratyphi C strains harbor a pil operon very similar to that of serovar Typhi. An important difference, however, is located in the shufflon which concludes the pil operon. In serovar Typhi, the Rci recombinase acts upon two 19-bp inverted repeats to invert the terminal region of the pilV gene, thereby disrupting PilV synthesis and permitting bacterial self-association. In serovar Paratyphi C, however, the shufflon is essentially inactive because each of the Rci 19-bp substrates has acquired a single base pair insertion. A PilV protein is thus synthesized whenever the pil operon is active, and bacterial self-association therefore does not occur in serovar Paratyphi C. The data thus suggest that serovar Typhi bacterial self-association using type IVB pili may be important in the pathogenesis of epidemic enteric fever.

In Vitro Activation of a Nonproductive Immunoglobulin Allele by a Single Base Pair Insertion

Hybridoma ◽  
1994 ◽  
Vol 13 (4) ◽  
pp. 257-261
Author(s):  
BARRY J. KOBRIN ◽  
CAROLYN SCHIFF ◽  
DANA ZIVION ◽  
MATTHEW D. SCHARFF ◽  
GADI SPIRA1
Keyword(s):  
Base Pair ◽  
Single Base ◽  
In Vitro Activation ◽  
Single Base Pair ◽  
Base Pair Insertion

scholarly journals SEQUENCING STUDIES OF ICR-170 MUTAGENIC SPECIFICITY IN THE am (NADP-SPECIFIC GLUTAMATE DEHYDROGENASE) GENE OF NEUROSPORA CRASSA

Genetics ◽  
1986 ◽  
Vol 113 (1) ◽  
pp. 45-51
Author(s):  
Philip A Burns ◽  
Jane H Kinnaird ◽  
Brian J Kilbey ◽  
John R S Fincham
Keyword(s):  
Neurospora Crassa ◽  
Base Pair ◽  
Uv Light ◽  
Base Pairs ◽  
Single Base ◽  
Base Pair Deletion ◽  
Dehydrogenase Gene ◽  
Sequencing Studies ◽  
Single Base Pair ◽  
Base Pair Insertion

ABSTRACT The acridine half-mustard ICR-170-induced reversion of the mutant am15, which has a single base-pair deletion, at a frequency of between 9 and 28 × 10-6. In each of three classes of revertants, the mutagen had induced the insertion of a (see PDF) base pair at a (see PDF) site. The mutant am6, which has a single base pair insertion, is known to be revertible, with UV light, by deletion of a (see PDF) base pair at a (see PDF) site. This mutant reverted with ICR-170 at a frequency of 0.1 × 10-6. These results show that ICR-170 is able to induce addition frameshifts in Neurospora crassa within short, monotonous runs of G:C base pairs, but indicate a lack of deletion activity at such sequences.

scholarly journals The Salmonella enterica Serovar Typhi Type IVB Self-Association Pili Are Detached from the Bacterial Cell by the PilV Minor Pilus Proteins

2006 ◽  
Vol 74 (9) ◽  
pp. 5414-5418 ◽  
Author(s):  
Connie K. P. Tam ◽  
Christina Morris ◽  
Jim Hackett
Keyword(s):  
Typhoid Fever ◽  
Bacterial Cell ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Dna Supercoiling ◽  
Bacterial Membrane ◽  
Salmonella Enterica Serovar Typhi ◽  
Protein Molecules ◽  
Dna Fragment ◽  
Self Association

ABSTRACT Salmonella enterica serovar Typhi and some strains (Vi+) of serovar Dublin use type IVB pili to facilitate bacterial self-association, but only when the PilV proteins (potential minor pilus proteins) are not synthesized. Pilus-mediated self-association may be important in the pathogenesis of enteric fever. We have shown previously that the extent of DNA supercoiling controls the rate of Rci-catalyzed inversion of a DNA fragment which includes the C-terminal portions of the PilV proteins. This inversion therefore controls PilV synthesis as a high inversion rate prohibits transcription of pilV-encoding DNA. Here, we describe the manner in which PilV protein expression inhibits bacterial self-association and present data which suggest that incorporation of one or a few PilV protein molecules into a growing pilus, comprised of PilS subunits, causes the pilus to detach at the bacterial membrane. The bacteria are then unable to self-associate. We suggest that this phenomenon may be relevant to the pathogenesis of typhoid fever.

Neuronal ceroid lipofuscinosis in Salukis is caused by a single base pair insertion inCLN8

2018 ◽  
Vol 49 (1) ◽  
pp. 52-58 ◽  
Author(s):  
F. Lingaas ◽  
O-A. Guttersrud ◽  
E. Arnet ◽  
A. Espenes
Keyword(s):  
Base Pair ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Single Base ◽  
Ceroid Lipofuscinosis ◽  
Single Base Pair ◽  
Base Pair Insertion

Whole exome sequencing identified a novel single base pair insertion mutation in the EYS gene in a six generation family with retinitis pigmentosa

2017 ◽  
Vol 58 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Jamil Amjad Hashmi ◽  
Maan Abdullah Albarry ◽  
Ahmed M. Almatrafi ◽  
Alia M. Albalawi ◽  
Amer Mahmood ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Exome Sequencing ◽  
Whole Exome Sequencing ◽  
Base Pair ◽  
Insertion Mutation ◽  
Single Base ◽  
Whole Exome ◽  
Generation Family ◽  
Single Base Pair ◽  
Base Pair Insertion

scholarly journals Overexpression of the MtrC-MtrD-MtrE Efflux Pump Due to an mtrR Mutation Is Required for Chromosomally Mediated Penicillin Resistance in Neisseria gonorrhoeae

2002 ◽  
Vol 184 (20) ◽  
pp. 5619-5624 ◽  
Author(s):  
Wendy L. Veal ◽  
Robert A. Nicholas ◽  
William M. Shafer
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Base Pair ◽  
Efflux Pump ◽  
Penicillin Resistance ◽  
Single Base ◽  
Base Pair Deletion ◽  
Resistance To Penicillin ◽  
Single Base Pair ◽  
High Level ◽  
Level Resistance

ABSTRACT The importance of the mtrCDE-encoded efflux pump in conferring chromosomally mediated penicillin resistance on certain strains of Neisseria gonorrhoeae was determined by using genetic derivatives of penicillin-sensitive strain FA19 bearing defined mutations (mtrR, penA, and penB) donated by a clinical isolate (FA6140) expressing high-level resistance to penicillin and antimicrobial hydrophobic agents (HAs). When introduced into strain FA19 by transformation, a single base pair deletion in the mtrR promoter sequence from strain FA6140 was sufficient to provide high-level resistance to HAs (e.g., erythromycin and Triton X-100) but only a twofold increase in resistance to penicillin. When subsequent mutations in penA and porIB were introduced from strain FA6140 into strain WV30 (FA19 mtrR) by transformation, resistance to penicillin increased incrementally up to a MIC of 1.0 μg/ml. Insertional inactivation of the gene (mtrD) encoding the membrane transporter component of the Mtr efflux pump in these transformant strains and in strain FA6140 decreased the MIC of penicillin by 16-fold. Genetic analyses revealed that mtrR mutations, such as the single base pair deletion in its promoter, are needed for phenotypic expression of penicillin and tetracycline resistance afforded by the penB mutation. As penB represents amino acid substitutions within the third loop of the outer membrane PorIB protein that modulate entry of penicillin and tetracycline, the results presented herein suggest that PorIB and the MtrC-MtrD-MtrE efflux pump act synergistically to confer resistance to these antibiotics.

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