scholarly journals Resistance to 16-Membered Macrolides, Tiamulin and Lincomycin in a Swine Isolate of Acholeplasma laidlawii

Antibiotics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1415
Author(s):  
María M. Tavío ◽  
Ana S. Ramírez ◽  
Carlos Poveda ◽  
Rubén S. Rosales ◽  
Cristina F. Malla ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dna Sequence ◽  
Ribosomal Proteins ◽  
Stop Codon ◽  
Opportunistic Pathogen ◽  
23S Rrna ◽  
Nucleotide Substitutions ◽  
Resistance Determinants ◽  
Microdilution Method

Acholeplasma (A.) laidlawii is an opportunistic pathogen with the ability to disseminate resistance determinants to antibiotics; however, its resistance to macrolides has been less studied. The aim of the present study was to characterize the mechanisms responsible for the resistance to macrolides, tiamulin and lincomycin found in a strain of A. laidlawii isolated from a pig with pneumonia. MICs of erythromycin, 15- and 16-membered macrolides, tiamulin and lincomycin were determined by microdilution method with and without reserpine, an inhibitor of ABC efflux pumps and regions of the genome were sequenced. Reserpine only decreased lincomycin MIC but it did not change the MICs of macrolides and tiamulin. The analysis of the DNA sequence of 23S rRNA showed nucleotide substitutions at eight different positions, although none of them were at positions previously related to macrolide resistance. Five mutations were found in the L22 protein, one of them at the stop codon. In addition, two mutations were found in the amino acid sequence of L4. The combination of multiple mutations in the ribosomal proteins L22 and L4 together with substitutions in 23S rRNA DNA sequence was associated with the resistance to macrolides, the pleuromutilin and lincomycin in the studied A. laidlawii strain.

scholarly journals Cloning, sequencing and heterologous expression of a cDNA encoding pigeon liver carnitine acetyltransferase

1995 ◽  
Vol 305 (2) ◽  
pp. 439-444 ◽  
Author(s):  
T M Johnson ◽  
H P Kocher ◽  
R C Anderson ◽  
G M Nemecek
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Heterologous Expression ◽  
Stop Codon ◽  
Expression System ◽  
Breast Muscle ◽  
Cdna Clones ◽  
Carnitine Acetyltransferase ◽  
Western Blots ◽  
Pigeon Liver

Two overlapping cDNA clones encoding pigeon liver carnitine acetyltransferase (EC 2.3.1.7) (CAT) were isolated from a pigeon liver lambda gt11 cDNA library by gene amplification using oligonucleotide primers based on the N-terminal amino acid sequence of the enzyme. The two clones, which represent the 5′ and 3′ ends of the gene, were spliced together to form a single cDNA construct containing the entire coding sequence for CAT, with an in-frame TGA stop codon 42 bases before the first ATG start site and a 3′-untranslated segment of 1057 bases. The largest open reading frame of 1942 nucleotides predicted a polypeptide of 627 amino acids and a molecular mass of 71.1 kDa. The N-terminus and four internal peptides from the amino acid sequence of pigeon breast muscle CAT were identified in the predicted sequence of the liver cDNA clone. The identity of the CAT cDNA was confirmed by heterologous expression of active recombinant CAT (rCAT) in insect cells using the baculovirus expression system. Western blots of rCAT from infected insect cell lysates and immunodetection with a rabbit anti-CAT polyclonal serum showed an immunoreactive protein band similar in size to native CAT from pigeon breast muscle. Like the native enzyme, rCAT was capable of acylating carnitine with a preference for small-chain acyl-CoAs of carbon chain lengths C2-C4.

scholarly journals DNA sequence of the E.coli trpR gene and prediction of the amino acid sequence of Trp repressor

1980 ◽  
Vol 8 (7) ◽  
pp. 1551-1560 ◽  
Author(s):  
C.K. Singleton ◽  
W.D. Roeder ◽  
Gregg Bogosian ◽  
R.L. Somerville ◽  
H.L. Weith
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Dna Sequence ◽  
Trp Repressor

Molecular dissection of membrane-transport proteins: mass spectrometry and sequence determination of the galactose–H+ symport protein, GalP, of Escherichia coli and quantitative assay of the incorporation of [ring-2-13C]histidine and 15NH3

2002 ◽  
Vol 363 (2) ◽  
pp. 243-252 ◽  
Author(s):  
Henrietta VENTER ◽  
Alison E. ASHCROFT ◽  
Jeffrey N. KEEN ◽  
Peter J.F. HENDERSON ◽  
Richard B. HERBERT
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Membrane Transport ◽  
Dna Sequence ◽  
Transport Proteins ◽  
Tandem Ms ◽  
Esi Ms ◽  
Membrane Transport Proteins ◽  
Ms Analysis

The molecular mass of the galactose—H+ symport protein GalP, as its histidine-tagged derivative GalP(His)6, has been determined by electrospray MS (ESI-MS) with an error of <0.02%. One methionine residue, predicted to be present from the DNA sequence, was deduced to be absent. This is a significant advance on the estimation of the molecular masses of membrane-transport proteins by SDS/PAGE, where there is a consistent under-estimation of the true molecular mass due to anomalous electrophoretic migration. Addition of a size-exclusion chromatography step after Ni2+-nitrilotriacetate affinity purification was essential to obtain GalP(His)6 suitable for ESI-MS. Controlled trypsin, trypsin+chymotrypsin and CNBr digestion of the protein yielded peptide fragments suitable for ESI-MS and tandem MS analysis, and accurate mass determination of the derived fragments resulted in identification of 82% of the GalP(His)6 protein. Tandem MS analysis of selected peptides then afforded 49% of the actual amino acid sequence of the protein; the absence of the N-terminal methionine was confirmed. Matrix-assisted laser-desorption ionization MS allowed identification of one peptide that was not detected by ESI-MS. All the protein/peptide mass and sequence determinations were in accord with the predictions of amino acid sequence deduced from the DNA sequence of the galP gene. [ring-2-13C]Histidine was incorporated into GalP(His)6in vivo, and ESI-MS analysis enabled the measurement of a high (80%) and specific incorporation of label into the histidine residues in the protein. MS could also be used to confirm the labelling of the protein by 15NH3 (93% enrichment) and [19F]tryptophan (83% enrichment). Such MS measurements will serve in the future analysis of the structures of membrane-transport proteins by NMR, and of their topology by indirect techniques.

Purification, properties, and N-terminal amino acid sequence of certain 50S ribosomal subunit proteins from the archaebacterium Halobacterium cutirubrum

1984 ◽  
Vol 62 (6) ◽  
pp. 426-433 ◽  
Author(s):  
Alastair T. Matheson ◽  
Makoto Yaguchi ◽  
Patricia Christensen ◽  
C. Fernand Rollin ◽  
Sadiq Hasnain
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Sequence Homology ◽  
Ribosomal Proteins ◽  
Large Subunit ◽  
Ribosomal Subunit ◽  
Terminal Amino Acid ◽  
Terminal Amino ◽  
Terminal Amino Acid Sequence

Sixteen ribosomal proteins (r-proteins) from the 50S ribosomal subunit of the archaebacterium Halobacterium cutirubrum have been purified and their amino acid composition and partial N-terminal amino acid sequence have been determined. These proteins as a group are much more acidic than the large subunit r-proteins from eubacteria or eukaryotes. Little sequence homology is evident between the 50S subunit archaebacterial r-proteins and the equivalent proteins from the eubacterium Escherichia coli.

scholarly journals Ribosomal proteins L34 and S29 of amphioxus Branchiostoma belcheri tsingtauense: cDNAs cloning and gene copy number.

2005 ◽  
Vol 52 (4) ◽  
pp. 857-862 ◽  
Author(s):  
Lina Liu ◽  
Shicui Zhang ◽  
Zhenhui Liu ◽  
Hongyan Li ◽  
Mei Liu ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Ribosomal Proteins ◽  
Amino Acid Sequence Identity ◽  
Fruit Fly ◽  
Calculated Molecular Mass ◽  
Sequence Identity ◽  
Acid Protein ◽  
Branchiostoma Belcheri ◽  
Amino Acid Protein

The complete cDNA and deduced amino-acid sequences of ribosomal proteins L34 (AmphiL34) and S29 (AmphiS29) from the amphioxus Branchiostoma belcheri tsingtauense were identified in this study. The AmphiL34 cDNA is 435 nucleotides in length and encodes a 118 amino-acid protein with calculated molecular mass of 13.6 kDa. It shares 53.6-67.5% amino-acid sequence identity with its eukaryotic counterparts including human, mouse, rat, pig, frog, catfish, fruit fly, mosquito, armyworm, nematode and yeast. The AmphiS29 cDNA comprises 453 nucleotides and codes for a 56 amino-acid protein with a calculated molecular mass of 6.6 kDa. It shows 66.1-78.6% amino-acid sequence identity to eukaryotic S29 proteins from human, mouse, rat, pig, zebrafish, seahorse, fruit fly, nematode, sea hare and yeast. AmphiL34 contains a putative nucleolar localization signal, while AmphiS29 has a zinc finger-like domain. A phylogenetic tree deduced from the conserved sequences of AmphiL34 and AmphiS29 and other known counterparts indicates that the positions of AmphiL34/AmphiS29 are intermediate between the vertebrate and invertebrate L34/S29. Southern blot analysis demonstrates the presence of one copy of the L34 gene and 2-3 copies of the S29 gene in the genome of the amphioxus B. belcheri tsingtauense. This is in sharp contrast to the existence of 7-9 copies of the L34 gene and 14-17 copies of the S29 gene in the rat genome. These date suggest that housekeeping genes like AmphiL34 and AmphiS29 have undergone large-scale duplication in the chordate lineage.

scholarly journals Two New Mechanisms of Macrolide Resistance in Clinical Strains ofStreptococcus pneumoniae from Eastern Europe and North America

2000 ◽  
Vol 44 (12) ◽  
pp. 3395-3401 ◽  
Author(s):  
A. Tait-Kamradt ◽  
T. Davies ◽  
P. C. Appelbaum ◽  
F. Depardieu ◽  
P. Courvalin ◽  
...  
Keyword(s):  
Amino Acid ◽  
North America ◽  
Eastern Europe ◽  
Ribosomal Proteins ◽  
Fold Increase ◽  
The United States ◽  
Resistance Mechanisms ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Isogenic Strains

ABSTRACT Resistance to macrolides in pneumococci is generally mediated by methylation of 23S rRNA via erm(B) methylase which can confer a macrolide (M)-, lincosamide (L)-, and streptogramin B (SB)-resistant (MLSB) phenotype or by drug efflux via mef(A) which confers resistance to 14- and 15-membered macrolides only. We studied 20 strains with unusual ML or MSB phenotypes which did not harbor erm(B) ormef(A). The strains had been isolated from patients in Eastern Europe and North America from 1992 to 1998. These isolates were found to contain mutations in genes for either 23S rRNA or ribosomal proteins. Three strains from the United States with an ML phenotype, each representing a different clone, were characterized as having an A2059G (Escherichia coli numbering) change in three of the four 23S rRNA alleles. Susceptibility to macrolides and lincosamides decreased as the number of alleles in isogenic strains containing A2059G increased. Sixteen MSB strains from Eastern Europe were found to contain a 3-amino-acid substitution (69GTG71 to TPS) in a highly conserved region of the ribosomal protein L4 (63KPWRQKGTGRAR74). These strains formed several distinct clonal types. The single MSB strain from Canada contained a 6-amino-acid L4 insertion (69GTGREKGTGRAR), which impacted growth rate and also conferred a 500-fold increase in MIC on the ketolide telithromycin. These macrolide resistance mechanisms from clinical isolates are similar to those recently described for laboratory-derived mutants.

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