scholarly journals Specificities of IncF plasmid conjugation genes

1986 ◽  
Vol 47 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Neil Willetts ◽  
John Maule
Keyword(s):  
Amino Acid ◽  
Recipient Cell ◽  
Amino Acid Sequences ◽  
Evolutionary Relationships ◽  
Gene Products ◽  
Dna Homology ◽  
Primary Amino ◽  
Acting In Concert ◽  
Surface Exclusion ◽  
Plasmid Conjugation

SummaryThe conjugation regions of IncF plasmids are closely related in that they share extensive DNA homology, and that they specify related pili. Variations between individual conjugation gene products of different IncF plasmids have, however, been noted. We have extended these observations by carrying out a systematic survey of twelve such plasmids, to examine the numbers and the groupings of the plasmid-specific alleles of several genes required for conjugation and its control.Using vector plasmids carrying cloned origins of transfer (oriT), four different specificities were recognized, and these were correlated with the specificities of the genes with products that may act at this site (traM, traYandtraZ). ThetraYgene is the first gene of the major transfer operon, and is therefore located close to the site at which thetraJprotein acts to induce expression of the operon: correspondingly, correlation was observed between theoriT/traMYZandtraJspecificities in most of the plasmids. In turn,traJis negatively regulated by thefinOandfinPproducts acting in concert: thefinOproduct was relatively non-specific, but sixfinPalleles were identified, again with specificities correlated with those oftraJ. Our explanation for this unexpectedly large number offinPalleles derives from the concept that thefinPproduct is an RNA molecule rather than a protein. Although the conjugative pili encoded by IncF plasmids are closely related, they confer different efficiencies of plating of the various F-specific bacteriophages. We distinguished four groups on this basis, presumably resulting from differences in the primary amino-acid sequences of the pilin proteins. These groups could be related to the surface exclusion system specificities, consistent with the hypothesis that surface exclusion acts at least in part by preventing interaction between the pilus and the recipient cell surface.From these data, information about the evolutionary relationships between the twelve IncF plasmids can be deduced.

scholarly journals Molecular Analysis of Resistance to Streptogramin A Compounds Conferred by the Vga Proteins of Staphylococci

2005 ◽  
Vol 49 (3) ◽  
pp. 973-980 ◽  
Author(s):  
Olivier Chesneau ◽  
Heidi Ligeret ◽  
Negin Hosan-Aghaie ◽  
Anne Morvan ◽  
Elie Dassa
Keyword(s):  
Antibiotic Resistance ◽  
Amino Acid ◽  
Sequence Analysis ◽  
Polyclonal Antibodies ◽  
Amino Acid Sequences ◽  
Gene Products ◽  
Β Subunit ◽  
Abc Proteins ◽  
Gram Positive Bacteria ◽  
Resistance Determinants

ABSTRACT The Vga and Msr resistance determinants, encoded by mobile genetic elements in various staphylococcal strains, belong to a family of ATP-binding cassette (ABC) proteins whose functions and structures are ill defined. Their amino acid sequences are similar to those of proteins involved in the immunity of streptomycetes to the macrolide-lincosamide-streptogramin antibiotics that they produce. Sequence analysis of the genomes of the gram-positive bacteria with low G+C contents revealed that Lmo0919 from Listeria monocytogenes is more closely related to Vga variants than to Msr variants. In the present study we compared the antibiotic resistance profiles conferred by the Vga-like proteins in two staphylococcal hosts. It was shown that Vga(A), the Vga(A) variant [Vga(A)v], and Lmo0919 can confer resistance to lincosamides and streptogramin A compounds, while only Vga(B) is able to increase the level of resistance to pristinamycin, a mixture of streptogramin A and streptogramin B compounds. By using polyclonal antibodies, we found that the Vga(A) protein colocalized with the β subunit of the F1-F0 ATPase in the membrane fractions of staphylococcal cells. In order to identify functional units in these atypical ABC proteins, such as regions that might be involved in substrate specificity and/or membrane targeting, we analyzed the resistance phenotypes conferred by various plasmids carrying parts or modified versions of the vga(A) gene and we determined the subcellular localization of the gene products. Only polypeptides composed of two ABC domains were detected in the cell membranes. No region of drug specificity was identified. Resistance properties were dependent on the integrities of both Walker B motifs.

scholarly journals Amino acid sequence and the cellular location of the Na+-dependent d-glucose symporters (SGLT1) in the ovine enterocyte and the parotid acinar cell

1995 ◽  
Vol 312 (1) ◽  
pp. 293-300 ◽  
Author(s):  
P S Tarpey ◽  
I S Wood ◽  
S P Shirazi-Beechey ◽  
R B Beechey
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Amino Acid Sequences ◽  
Primary Amino Acid Sequence ◽  
Parotid Acinar Cells ◽  
Parotid Acinar Cell ◽  
Primary Amino

The Na(+)-dependent D-glucose symporter has been shown to be located on the basolateral domain of the plasma membrane of ovine parotid acinar cells. This is in contrast to the apical location of this transporter in the ovine enterocyte. The amino acid sequences of these two proteins have been determined. They are identical. The results indicated that the signals responsible for the differential targeting of these two proteins to the apical and the basal domains of the plasma membrane are not contained within the primary amino acid sequence.

scholarly journals The two alpha-tubulin genes of Chlamydomonas reinhardi code for slightly different proteins.

1985 ◽  
Vol 5 (9) ◽  
pp. 2389-2398 ◽  
Author(s):  
C D Silflow ◽  
R L Chisholm ◽  
T W Conner ◽  
L P Ranum
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Gene Products ◽  
Beta Tubulin ◽  
Alpha Tubulin ◽  
Tubulin Genes ◽  
Total Complement ◽  
Cloned Gene ◽  
Net Charges

Full-length cDNA clones corresponding to the transcripts of the two alpha-tubulin genes in Chlamydomonas reinhardi were isolated. DNA sequence analysis of the cDNA clones and cloned gene fragments showed that each gene contains 1,356 base pairs of coding sequence, predicting alpha-tubulin products of 451 amino acids. Of the 27 nucleotide differences between the two genes, only two result in predicted amino acid differences between the two gene products. In the more divergent alpha 2 gene, a leucine replaces an arginine at amino acid 308, and a valine replaces a glycine at amino acid 366. The results predicted that two alpha-tubulin proteins with different net charges are produced as primary gene products. The predicted amino acid sequences are 86 and 70% homologous with alpha-tubulins from rat brain and Schizosaccharomyces pombe, respectively. Each gene had two intervening sequences, located at identical positions. Portions of an intervening sequence highly conserved between the two beta-tubulin genes are also found in the second intervening sequence of each of the alpha genes. These results, together with our earlier report of the beta-tubulin sequences in C. reinhardi, present a picture of the total complement of genetic information for tubulin in this organism.

scholarly journals Proteome-wide signatures of function in highly diverged intrinsically disordered regions

2019 ◽  
Author(s):  
Taraneh Zarin ◽  
Bob Strome ◽  
Alex N Nguyen Ba ◽  
Simon Alberti ◽  
Julie D Forman-Kay ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Functional Annotations ◽  
Intrinsically Disordered ◽  
Intrinsically Disordered Regions ◽  
Molecular Features ◽  
Primary Amino ◽  
Function Relationship ◽  
Disordered Regions

AbstractIntrinsically disordered regions make up a large part of the proteome, but the sequence-to-function relationship in these regions is poorly understood, in part because the primary amino acid sequences of these regions are poorly conserved in alignments. Here we use an evolutionary approach to detect molecular features that are preserved in the amino acid sequences of orthologous intrinsically disordered regions. We find that most disordered regions contain multiple molecular features that are preserved, and we define these as “evolutionary signatures” of disordered regions. We demonstrate that intrinsically disordered regions with similar evolutionary signatures can rescue functionin vivo,and that groups of intrinsically disordered regions with similar evolutionary signatures are strongly enriched for functional annotations and phenotypes. We propose that evolutionary signatures can be used to predict function for many disordered regions from their amino acid sequences.

Expression and Regulation of the Arsenic Resistance Operon of Acidiphilium multivorum AIU 301 Plasmid pKW301 in Escherichia coli

1998 ◽  
Vol 64 (2) ◽  
pp. 411-418 ◽  
Author(s):  
Katsuhisa Suzuki ◽  
Norio Wakao ◽  
Tetsuya Kimura ◽  
Kazuo Sakka ◽  
Kunio Ohmiya
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Constitutive Expression ◽  
Amino Acid Sequences ◽  
Gene Products ◽  
Arsenic Resistance ◽  
E Coli ◽  
Molecular Weights ◽  
Rna Polymerase Promoter ◽  
Extension Analysis

ABSTRACT The arsenic resistance (ars) operon from plasmid pKW301 of Acidiphilium multivorum AIU 301 was cloned and sequenced. This DNA sequence contains five genes in the following order: arsR, arsD, arsA,arsB, arsC. The predicted amino acid sequences of all of the gene products are homologous to the amino acid sequences of the ars gene products of Escherichia coliplasmid R773 and IncN plasmid R46. The ars operon cloned from A. multivorum conferred resistance to arsenate and arsenite on E. coli. Expression of the arsgenes with the bacteriophage T7 RNA polymerase-promoter system allowedE. coli to overexpress ArsD, ArsA, and ArsC but not ArsR or ArsB. The apparent molecular weights of ArsD, ArsA, and ArsC were 13,000, 64,000, and 16,000, respectively. A primer extension analysis showed that the ars mRNA started at a position 19 nucleotides upstream from the arsR ATG in E. coli. Although the arsR gene of A. multivorum AIU 301 encodes a polypeptide of 84 amino acids that is smaller and less homologous than any of the other ArsR proteins, inactivation of the arsR gene resulted in constitutive expression of the ars genes, suggesting that ArsR of pKW301 controls the expression of this operon.

AnEimeriavaccine candidate appears to be lactate dehydrogenase; characterization and comparative analysis

Parasitology ◽  
2004 ◽  
Vol 128 (6) ◽  
pp. 603-616 ◽  
Author(s):  
D. SCHAAP ◽  
G. ARTS ◽  
J. KROEZE ◽  
R. NIESSEN ◽  
S. V. ROOSMALEN-VOS ◽  
...  
Keyword(s):  
Amino Acid ◽  
Lactate Dehydrogenase ◽  
3D Model ◽  
Amino Acid Sequences ◽  
Evolutionary Divergence ◽  
Model Structure ◽  
Partial Protection ◽  
Primary Amino ◽  
The Many ◽  
Intracellular Stage

AnEimeria acervulinaprotein fraction was identified which conferred partial protection against anE. acervulinachallenge infection. From this fraction a 37 kDa protein was purified and its corresponding cDNA was cloned and shown to encode a lactate dehydrogenase (LDH). Full length cDNAs encoding LDH from two related species,E. tenellaandE. maxima, were also cloned. The homology between the primary amino acid sequences of these threeEimeriaLDH enzymes was rather low (66–80%), demonstrating an evolutionary divergence. ThePlasmodiumLDH crystal structure was used to generate a 3D-model structure ofE. tenellaLDH, which demonstrated that the many variations in the primary amino acid sequences (P. falciparumLDH andE. tenellaLDH show only 47% identity) had not resulted in altered 3D-structures. Only a single LDH gene was identified inEimeria, which was active as a homotetramer. The protein was present at similar levels throughout different parasitic stages (oocysts, sporozoites, schizonts and merozoites), but its corresponding RNA was only observed in the schizont stage, suggesting that its synthesis is restricted to the intracellular stage.

scholarly journals Galactan-binding antibodies. Diversity and structure of idiotypes.

1983 ◽  
Vol 158 (5) ◽  
pp. 1385-1400 ◽  
Author(s):  
S Rudikoff ◽  
M Pawlita ◽  
J Pumphrey ◽  
E Mushinski ◽  
M Potter
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Molecular Basis ◽  
Sequence Variation ◽  
Amino Acid Sequences ◽  
Repair Enzymes ◽  
Nucleotide Addition ◽  
Recombination Processes ◽  
Strong Homology ◽  
Primary Amino

A group of eight IgM hybridoma proteins induced with beta(1,6)-D-galactan-containing antigens has been characterized in terms of primary amino acid sequence and idiotype expression. The H chain amino acid sequences reveal very strong homology in the VH segment although several substitutions are seen that suggest the occurrence of somatic mutation in these IgM molecules. Significant sequence variation was observed in CDR-3, the region generated by the D segment, and the two recombination events, VH-D and D-JH. The number of amino acids in this region contributed by the D segment was found to vary from two to six, yet the overall length of CDR-3 was precisely maintained by the addition of amino acids on either side of D during the recombination processes. These additional amino acids are suggested to result from nucleotide addition by repair enzymes. Idiotypic analysis of these proteins, in conjunction with an assessment of the H chain sequences, has permitted an identification of the molecular basis of both cross-reacting and unique idiotypic determinants expressed by these molecules.

scholarly journals A nuclear hormone receptor corepressor mediates transcriptional silencing by receptors with distinct repression domains.

1996 ◽  
Vol 16 (10) ◽  
pp. 5458-5465 ◽  
Author(s):  
I Zamir ◽  
H P Harding ◽  
G B Atkins ◽  
A Hörlein ◽  
C K Glass ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nuclear Receptors ◽  
Hormone Receptor ◽  
Transcriptional Repression ◽  
Hormone Receptors ◽  
Thyroid Hormone Receptor ◽  
Nuclear Hormone Receptor ◽  
Amino Acid Sequences ◽  
Orphan Receptor ◽  
Primary Amino

Ligand-independent transcriptional repression is an important function of nuclear hormone receptors. An interaction screen with the repression domain of the orphan receptor RevErb identified N-CoR, the corepressor for thyroid hormone receptor (TR) and retinoic acid receptor (RAR). N-CoR is likely to be a bona fide transcriptional corepressor for RevErb because (i) RevErb interacts with endogenous N-CoR, (ii) ectopic N-CoR potentiates RevErb-mediated repression, and (iii) transcriptional repression by RevErb correlates with its ability to bind N-CoR. Remarkably, a region homologous to the CoR box which is necessary for TR and RAR to interact with N-CoR is not required for RevErb. Rather, two short regions of RevErb separated by approximately 200 amino acids are required for interaction with N-CoR. The primary amino acid sequence of the N-terminal region of RevErb essential for N-CoR interaction is not homologous to that of TR or RAR, whereas similarities exist among the C-terminal domains of the receptors. N-CoR contains two adjacent but distinct interaction domains, one of which binds tightly to both RevErb and TR whereas the other binds more weakly and differentially interacts with the nuclear receptors. These results indicate that multiple nuclear receptors, utilizing different primary amino acid sequences, repress transcription by interacting with N-CoR.

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